Endometriosis & The Bowel

Diagram of human bowels

As you may know, Endometriosis is not limited to just your reproductive bits & pieces.  It can implant, grow, and fester in many places; the bowel included.  But what does that mean? How do you know if it’s on your bowel?  Today’s blog will go into that…Read on, dear Reader…read on.  Word of warning : I will be using words like fart and poop! Why dance around the subject with flowery words when I feel like I’m a giggly 12-year-old girl?

It is estimated that between 5-15% (and some even doctors guess it’s actually between 3-34%) of women with Endometriosis suffer from Endo on their bowels.  Bowel Endometriosis may affect the colon, the rectum, the large intestine, the small intestine, the colon, or the sigmoid colon.  The implants may be physically located on the bowels, or even just located adjacent to them in areas like the Pouch of Douglas, uterosacral ligaments, or rectovaginal septum. The close proximity of the inflamed and irritated lesions may be enough to induce bowel Endometriosis symptoms.  And these symptoms may also be caused by adhesions pulling or twisting the bowels.


Many symptoms worsen while an EndoWarrior is on their period; however, many also suffer from these symptoms all of the time…and some lucky few don’t suffer from any symptoms (aka Silent Endometriosis).  Endo on the bowel can cause pain in the abdomen, bowel, rectum, or rectal bleeding (especially while menstruating). You may feel pain while sitting, farting, pooping, or even having sex.  You may even suffer from difficulty pooping, constipation and/or diarrhea, or a sense that you haven’t fully voided after pooping.  Other symptoms may be that you feel full after eating just a small amount of food, suffer from bloating, lower back pain, cramping, nausea, decreased appetite, or vomiting.  

Bowel Endo and/or adhesions may cause a partial or full intestinal blockage.  If this occurs, constipation will worsen.  If completely blocked, you can suffer a perforation or tear in your colon which may lead to an infection (which may be fatal…read about Emelia).  If the blockage is severe, surgery may be required to clear it or resect (remove a portion of) the damaged bowel. Heck, even if the blockage isn’t severe, a resection may be the best way to remove any Endometriosis lesions from the exterior or interior of the intestinse.

Diagnostic Tests

Just like any case of Endometriosis, the first step toward diagnosis is a detailed medical and symptom history.  A physical examination may follow and one possible indicator of bowel Endo is a tender spot inside the vagina near the rectum (this may indicate Endo on the Pouch of Douglas).  Dr. Redwine explains the cul-de-sac (aka the Pouch of Douglas) involvement a little bit better,

“When the rectum is involved by endometriosis, it frequently scars forward to the back of the uterus, causing what is known as obliteration of the cul de sac. This indicates the presence of deeply invasive disease in the uterosacral ligaments, the cul de sac, and usually the front wall of the rectum itself with what is called a rectal nodule. The disease can occasionally invade the rear wall of the vagina as well.”

Studies indicate that people who have an obliterated Pouch of Douglas are three times more likely to have bowel Endo than someone without an obliterated cul-de-sac.

Transvaginal ultrasounds may also be beneficial if a physician suspects bowel Endo – those who have ovarian cysts have a 30% chance of having Endo on their bowels.  New studies are finding that transvaginal (and transrectum) ultrasounds may be able to “pick up” bowel lesions as masses on the screen and that they may hold a distinct shape of their own.

A CT scan or MRI may be conducted of your pelvic region to rule out other obstructions or masses, as written in this interesting article on the usefulness of pre-diagnosis with imaging studies.  Likewise, a colonoscopy, sigmoidoscopy, or barium enema may be used to rule out other GI illnesses; however, they often show up negative for Endometriosis.  That’s because the Endo often resides outside the bowel…not the inside…so these tests cannot detect Endo. But there are cases where “polyps” or “lesions” found in these internal tests have come back as positive for Endometriosis…or something that prompts more investigation.

And, as always, there’s a but: BUT many imaging studies may come back 100% completely normal and show no signs of bowel Endometriosis.

Unfortunately, the only way to confirm a suspected case of bowel Endo is to cut you open, look inside, and biopsy any discovered lesions.


Like all other forms of Endometriosis, the treatment is pretty much the same:

  • Patience – the Wait & See method – if the symptoms are bearable, ride them out.  Be patient.  Literally, wait and see what happens…or wait for your next surgery;
  • Medication – pain killers, NSAIDs, aromatase inhibitors, GnRH antagonists, birth control pills/IUD, or other medications may offer a reduction in symptoms; and,
  • Surgery – an excision surgery to remove the Endo implants from the pelvic cavity and bowel would be ideal. But there are those who practice ablation instead. The implants may be shaved from the exterior of the bowel, or a deeper-removal of the lesions may be necessary.  Some patients must undergo a bowel resection to remove a portion of the infected bowel if the Endometriosis is too deeply-implanted in the bowel.  Your Endo excision surgeon should enlist the help of a colorectal surgeon for this process, as there are risks of serious complications with bowel surgery.  Many patients return to a higher quality of life after their excision surgeries.

And, as usual, recurrence is always a possibility…


Dr. Doron Kopelman wrote, “Endometriosis has been described as the great masquerader,” which is so beautifully and (unfortunately) accurately written.  Endo on the bowel may be misdiagnosed and dismissed as many other GI issues.  Here are a few examples of common misdiagnoses:

  • Appendicitis – Endo in the ileum (lower right abdomen) causes pain which is often mistaken as an appendicitis.  The symptoms of an appendicitis can include right-sided abdominal pain, constipation, diarrhea, loss of appetite, and bloating.
  • Crohn’s Disease – symptoms include constipation, diarrhea, rectal bleeding, and abdominal cramping.
  • Diverticulitis – when pouches within the intestine become inflamed, infected, or bleed, the symptoms may be pain, diarrhea, constipation, tenderness, rectal bleeding, and cramping.
  • Gastrointestinal carcinoma – a small tumor within the intestines which cause very similar symptoms and/or blockages as bowel Endometriosis.
  • Irritable Bowel Syndrome (IBS) – symptoms of IBS and bowel Endo are very similar, including frequent constipation and diarrhea.  Dr. Kevin Sinervo addressed the 2013 Medical Conference hosted by The Endometriosis Foundation of America and discussed IBS and Endometriosis.  
  • Ischemic colitis – caused by an inadequate flow of oxygenated blood to the intestines, symptoms can include cramping, diarrhea, vomiting, and abdominal distension.
  • Pelvic inflammatory disease – symptoms may include abdominal pain and pain during/after intercourse.
  • Ulcerative colitis – symptoms of ulcerative colitis include an urgency to poop, diarrhea, bloody stool, and abdominal cramps.

And if this weren’t enough?  Think of the possibilities : a person may have both Endometriosis and any of these (or other) conditions.  One does not negate the other.  And just because you have symptoms of bowel Endo doesn’t mean you have bowel Endo…


There have been several studies about bowel Endometriosis, different treatments, different surgeries, various diagnostic tools…and the fact that even post-menopausal patients can develop bowel Endometriosis (with or without hormone replacement therapy).  Numerous studies!  They can be found below in the “Resources” section of this blog…scroll down.

A 2016 study followed the case of a 40-year-old woman who had a previous hysterectomy.  She was having bowel issues and a colonoscopy revealed a mass insider her rectum.  It was removed and biopsied, and diagnosed as Endometriosis.  This means it was INSIDE her bowel…The authors urge surgeons to be thorough in the removal of Endometriosis in any abdominal surgery, as recurrence an always happen, even post-hysterectomy.  They also urge patients to follow-up with any recurring symptoms.

A Jan. 2017 study offers an alternative to colorectal resection, if the situation merits it.  Rather than resecting a portion of the bowel, the authors of the study (published in Fertility & Sterility) offer a technique knows as The Rouen Technique, which removes nodules of Endometriosis found within the rectum. Of the 111 women in the study, most stated they had improved gastrointestinal quality of life.  Two of those women had a recurrence of the rectal Endometriosis within 2 years: one opted for birth control treatment and the other opted for a second excision using the Rouen Technique.  Although this study is self-admittedly weak (no control groups), you may want to print out the article and discuss this possible technique with your healthcare provider.

A Feb. 2017 study follows a 43-year-old woman who suffered from rectal bleeding and constipation.  She also had bloody stool during her periods, and burning rectal pain.She had suffered from constipation for several years and had just taken laxatives, abdominal pain, felt like she never quite cleared her bowels when she did poop, and had abdominal bloating.  Sh’d never undergone surgeries in the past, and hadn’t been diagnosed with any chronic illnesses.  The day of her visit, she didn’t have any abdominal bloating or pain, and her vitals were all normal; her rectal examination was normal.  She underwent a colonoscopy to rule out any causes of her symptoms: some of her sigmoid colon appeared red and angry, which a biopsy revealed as chronic inflammation.  She was also found to have hemorrhoids.  A second colonoscopy was performed and deeper tissue samples were taken; these newly-biopsied deeper samples were found to be Endometriosis.  A further medical history review found she had a history of Endometriosis (although how this was confirmed without any prior surgeries is beyond me).  She opted for a hysterectomy, removing both ovaries as well. Her symptoms disappeared.

A March 2017 case study was of a 58-year-old woman who suffered from chronic diarrhea and post-menopausal bleeding.  During a routine colonscopy, they found a mass extending from her rectum to her sigmoid colon.  Biopsies led the physicians to believe it to be Endometriosis.  A laparoscopy was performed, the mass was removed, as well as her uterus, cervix, fallopian tubes, and ovaries.  Endometriosis was also found on her cervix and the tissues between her uterus and bowel.

An April 2017 letter to the editor featured in Ultrasound in Obstetrics in Gynecology focuses on using high-intensity focused ultrasound energy to burn away deep infiltrating endometriosis that has infiltrated the rectosigmoid colon.  Many of us read “ablation” or “burning” and run away, but (butt?) in some instances, it may be the best option for the patient in order to avoid a total resection.

The International Journal of Surgery Case Reports published an article in late 2017 about a 46-year-old woman who went to the hospital because she had been throwing up, was constipated, and her abdomen had been swollen for the past two days.  Physicians suspected a small bowel obstruction and confirmed it with imaging studies.  The corrective was performed that same day and they found that endometriosis deposits had strictured (pinched off, so to speak) her small bowel.  They removed the affected section of bowel and biopsy confirmed the endometriosis diagnosis.  The obstruction cleared up after surgery and she was referred to her gynecologist for further management of her Endo.

In January of 2018, the Kaohsiung Journal of Medical Sciences wrote about a 43-year-old woman who had a medical history of chocolate cysts after an excision surgery and had (for the past two months) been having lower left abdominal pain and didn’t poop as much as she had been.  Her lower abdominal pain didn’t seem related to food or pooping, and she experienced bloody poop mostly during her menstrual cycle.  A physical exam of the lower left abdomen, as well as an internal exam (with a finger) were normal.  A colonoscopy found she had a mass inside her intestines.  It was surgically removed, along with a portion of her intestines, and confirmed as Endometriosis via biopsy tests.

In November of 2018, I went through my own surgery to remove Endometriosis from my bowel. It had been discovered on my small intestine at the ileocecal valve (where the small intestine meets the large intestine). I had a portion of my small intestine, my colon, my cecum, and my appendix removed. And I’m glad it did as it had created a sort of twisted mass of my guts.

Paripex published a study in January of 2019 of a 28-year-old woman who had a history of infertility and painful periods for seven years. An ultrasound found a mass in her adnexa, which was believed to be Endometriosis. An MRI scan showed a mass within her sigmoid colon. A colonoscopy was attempted, but the mass was so large, they camera could not pass the sigmoid colon. She underwent a laparoscopy and had normal reproductive organs, except she had a cyst on her left ovary. The cyst was removed, as was the portion of her blocked intestines. She underwent a second surgery due to constipation and vomiting, where dense adhesions were found around her bowel resection site. These were cleaned up and additional endometriosis lesions were discovered and she also received an ileostomy bag for the next three months. The bag was removed, her intestines rejoined, and she had no further complaints during follow-up.

A 2019 study published in Hindawi focused on a 41-year-old woman who had a medical history of painful periods and had a prior appendectomy. She went to the ER with nausea, vomiting, acute pain in her lower left torso, and had complained of weakness, fatigue, and weight loss for the last month. Her abdomen was distended and tender. A CT scan showed a mass in her cecum and a complete bowel obstruction. It also showed that her ovary was stuck to her uterus and that her bowels were inflamed. A laparotomy was performed and the cecum mass was found to also involve the ileocecal valve and caused a full blockage of her intestines. Some of her right colon (as well as the mass) were removed. The mass on her ovary was also removed. Pathology reports found that the bluish mass in her cecum blocked 90% of her ileocecal valve, her colon wall was invaded with microscopic evidence of Endometriosis, and the mass removed from the ovary was an Endometrioma. At her follow-up examination, she was symptom-free.

A 2019 study was of a 35-year-old woman who had complaints of constipation and bleeding from her rectum, mostly during her period. She also had bloating and lower abdominal pain. CT scans, barium enemas, a colonoscopy, and inconclusive punch biopsies led the physicians to believe she had a growth, possibly a carcinoma, inside her rectum. She underwent a bowel resection and they removed nearly 4.5 inches of her recto-sigmoid colon. Pathology reports showed that the growth was not a carcinoma; it was instead Endometriosis.

A 20-year-old woman was the focus of a March 2019 abstract published by an Italian journal. She complained of abdominal pain for the past 2 years and was referred to surgery by her psychiatrist. Endometriosis was found along her right pelvic area, her Pouch of Douglas, and her uterosacral ligaments. Nothing abnormal was found with her bowels. Eight days later, the cramps continued and she began to bleed from her butt. A second surgery was performed and they found evidence of a pelvic hematoma and rectosigmoiditis (ulcerative colitis). Three days later, they found fecal matter in her surgical drains. Another surgery was quickly scheduled and it was determined that her bowels had perforated and she received a bowel resection and ileostomy. Biopsy of the intestines found evidence of deep-infiltrating Endometriosis within the intestinal wall, and it’s surmised that caused the perforation. The study concludes, “The presented case confirms the importance of interdisciplinary cooperation between surgeons, gynaecologists, and pathologists. We also want to emphasize the need for extensive pathological examination of the resected specimens which is essential for a proper diagnosis.”

The Turkish Society of Colon and Rectal Surgery published a 2020 article about a 28-year-old female went to the hospital due to abdominal pain, lack of appetite, nausea, and vomiting. The pain had been ongoing for about a day and worsened over a six-hour period. An ultrasound was attempted, but was inconclusive because she had too much gas. A CT scan found contracted bowels and they believed she suffered from a small bowel obstruction. A laparotomy was performed and defect which caused a bowel obstruction near her ileocecal valve. They resected the portion of blocked bowels and pathology found the blockage to be “fibrosis caused by Endometriosis.” The patient was released from the hospital after a four-day stay with no complications. The authors end their study with a powerful statement: “Mechanical small-bowel obstruction due to ileal endometriosis is a rare case…[i]t does not resolve spontaneously and surgery is the treatment of choice.”

In June 2020, an article was published of a 37-year-old woman who was treated for a small bowel obstruction. Before being hospitalized for the obstruction, she had complaints of not being able to poop or fart for three days, suffered from chronic lower right abdominal pain and she was either always constipated or suffered from diarrhea. Sometimes she had blood in her stool. She also had complaints of painful periods and chronic pelvic pain. A CT scan found a small mass on her cecum, which appeared to have caused a bowel obstruction. Emergency surgery was performed, the mass and a portion of her right colon was removed, and she received a temporary ileostomy bag. Pathology showed Endometriosis of her cecum and ileocecal valve (hey, that’s where mine was!). She was in the hospital for 7 days and had a surgery three months later to reverse the ileostomy. Her chronic pelvic pain complaints dramatically reduced after both surgeries.

Another article published in June of 2020 followed the journey of a 32-year-old woman who complained of vomiting, diarrhea, and abdominal pain for two weeks. She was given pain killers, antibiotics, and a proton pump inhibitor, but did not improve. She’d never had these symptoms before. An ultrasound and CT scan revealed “intussusception”, which is when one portion of the intestine slips in and telescopes into another portion of intestine. An emergency laparotomy was ordered and she underwent a bowel resection. The intussusception was caused by adhesions and an Endometriosis lesion discovered in the colon. She was symptom-free three months after surgery.

Case Reports in Medicine published an article in July of 2020 about a 51-year-old woman in Brazil who had been hospitalized due to a decrease in bowel movements (she was only poopin’ once every three days), and her bowel movements were “sharp and long”. These complaints had been getting worse over the past year, and about once a month would have blood in her stool. The physical examination and labwork were normal. And it may be important to point out that she had a hysterectomy in 2011 due to fibroids. A CT scan showed abnormal thickening of of her upper rectum and sigmoid colon. A rigid sigmoidoscopy was performed and they physicians were unable to proceed more than 30cm (almost 12 inches) into her colon due to a blockage and there was mucosa along the interior of her bowels. They suspected colon cancer and performed surgery to remove the diseased portions of her intestines. Pathology corrected the pre-op diagnosis with findings of intestinal wall Endometriosis. After healed from her surgery, the patient had no recurrent symptoms.

In August 2020, Surgical Case Reports published an article of a 43-year-old woman who had been constipated for the past two years, but no abdominal pain. An x-ray revealed a lot of trapped gas (giggle), but a colonoscopy found a lesion in her upper rectum. On two separate occasions, samples of that lesion were taken and tested and came back as “nonspecific inflammation.” A CT scan showed wall thickening of that same section of her guts…and it also revealed a 4cm (a little bigger than 1.5 inches) cyst on her left ovary. An exploratory laparoscopy was performed: she had some fluid in her Pouch of Douglas an endometrioma on her left ovary, and some rectum adhesions. “No endometrium was found on the rectal surface or abdominal wall.” The upper rectum showed some signs of inflammation, which may have been a tumor. The patient opted for a bowel resection to remove that defect and lymph node surgery (her surgery was 7 hours long!)! The left wall of the rectum was stuck to her left ovary and large amount of stool was still stuck within her colon. She received a temporary ileostomy and was discharged home after nearly 40 days in the hospital. WHAT A TROOPER!!! A biopsy of the intestines came back as rectal endometriosis. But you want to get angry: they left the endometrioma there…inside…”and the patient was attending a gynecological department for hormone therapy at the time of this writing.” UGH! I’m so frustrated. I mean, maybe they had a good reason to leave it in, but UGH!

Another study in August of 2020 was published in the Canadian Medical Association Journal. A 36-year-old woman went into the emergency room with a 9-month history of abdominal pain and rectal bleeding while she was on her period. A physical exam, labwork, and ultrasound were all normal. An MRI showed intestinal wall thickening of her sigmoid colon. And a colonoscopy showed a lesion with “red nodular surfaces” in her sigmoid colon. They suspected intestinal Endometriosis, as well as IBS or cancer. Although, pathology of the lesion from the colonoscopy came back as “nonspecific.” A second colonoscopy was conducted while the gal was on her period, and that pathology came back as intestinal endometriosis. The patient declined hormonal treatments and instead a bowel resection surgery occurred. They removed the section of her sigmoid colon and found no other evidence of any pelvic Endo.

On October 21, 2020, I underwent a second bowel resection due to Endometriosis that was discovered on my sigmoid colon during my May 2020 surgery. Prior to my resection, it hurt nearly every time I poo’d for the last several months: like glass and sandpaper scraping through my guts. And I had lower-left abdominal pain almost daily. A “defect” was found on my rectosigmoid junction and was removed. I also had Endometriosis in other areas of my pelvic cavity, which was also excised. And since then (today is January 1, 2021), I’ve been symptom-free and poopin’ with noooo pain! Woohoo!

A study published in October of 2020 is of a 38-year-old woman who complained of bleeding from the rectum, as well as abdominal pain, nausea, and vomiting for the past week. Physical examination confirmed she had tenderness in the lower left quadrant of her abdomen. A CT scan revealed an ovarian cyst and uterine fibroid, but that was all. A colonoscopy was performed and they found a large mass at her rectosigmoid junction (where the sigmoid colon and rectum meet). A biopsy was done and pathology found it to be Endometriosis. A sigmoidoscopy was later performed and the biopsy repeated, which confirmed the original Endometriosis findings. Her doctors threw a hysterectomy and taking her ovaries, but she declined because she one day wanted children. Instead, she started taking Norethindrone acetate and would seek out surgical treatment to deal with the bowel Endometriosis. The abstract ends without providing the outcome.

Another October 2020 study concerned a 36-year-old female who went to the ER with nausea, vomiting, and abdominal pain. A CT scan was done and showed she had “wall thickening” near the distal small bowel, including the little area that joins to the large intestine. A colonsocopy revealed that the terminal ileum (that small intestine/large intestine junction) had some patchy redness and watery fluid buildup. Biopsies were taken and pathology noted the tissue was “lymphoid aggregates”: harmless, non-cancerous little red bumpies. She was treated for a small bowel obstruction and sent home. They suspected she may have Crohn’s disease, so they started her on medication for such. Several months later, she returned for follow-up imaging of her bowels. It revealed the inflammation of her small intestine had only worsened and a fistula may have begun to form. Due to her ongoing symptoms and worsening inflammation, she underwent surgery and the portion of the inflamed bowels was removed. Can you guess what it was? Pathology found Endometriosis on her small intestines. Unfortunately, it doesn’t tell me how the patient was doing after surgery.

And yet a third October 2020 study from The American Journal of Gastroenterology discusses a 44-year-old female with IBS who went to the doctor with widespread abdominal pain and a previous “abnormal” CT scan. The physical examination and bloodwork were normal. Another CT scan showed a cyst on her left kidney and a mass in her cecum (the pouch at the left end of the large intestines). A colonoscopy showed that her cecum had twisted and had a small lesion on it. A biopsy led them to believe she had active colitis. An MRI was performed and showed a hard mass about an inch big at the tip of her cecum. A laparoscopic surgery ensued and they discovered a “puckered mass of the cecum” near the base of the appendix. The cecum was removed and pathology confirmed “extensive endometriosis of the colonic wall and 2 pericolic lymph nodes.” She was placed on oral contraceptives to manage her Endometriosis symptoms. No references to her outcome or further treatment.

Diseases of the Colon & Rectum published a November 2020 study of a 31-year-old woman who complained of bleeding from her rectum. A colonoscopy revealed a polyp…which was biopsied and came back as bowel Endometriosis. She had already had a scheduled Endometriosis excision surgery on calendar so her surgeons tacked on a bowel resection as well. At the time of the publication of the study, she had no recurrent symptoms.

In December 2020, The Japanese Society of Internal Medicine published an article about two cases of bowel Endometriosis. First, a 47-year-old woman had a colonoscopy due to a distended abdomen and complaints of diarrhea. She had a medical history of a hysterectomy, breast cancer, and thyroid cancer. Screening, labwork, and a physical examination came back with no abnormalities. However, the colonoscopy caught a small lesion on the wall of her cecum. Fifteen months later, she underwent another colonscopy, which showed the lesion had grown substantially. A CT scan confirmed the presence of the suspected tumor and she underwent a partial resection of that side of her colon. A biopsy found it was an Endometriosis lesion, the same was visible on that last CT scan. The second case was of a 38-year-old woman who had a colonoscopy prior to a hysterectomy. The colonoscopy found a lesion inside her cecum, too; however nothing showed up on a CT scan so they decided to leave it be and she had her hysterectomy, which also included removing her tubes and ovaries. Fast forward three years later and she had another colonoscopy: the lesion was still there inside her cecum and the CT scan revealed nothing suspicious. Three years later (now 44 years old), a follow-up colonoscopy showed the cecum-lesion was still present. Labwork and a physical examination was normal (again). Another colonoscopy showed that the lesion was present and the mass had caused the ileocecal valve to deform. A CT scan (this time with contrast-enhancement and carbon dioxide insufflation into the rectum) did find presence of the tumor and a bowel resection occurred. During the surgery, her appendix was noted to be inverted and removed as well. Pathology confirmed she had cecal endometriosis and appendiceal endometriosis. The authoris stress “these cases highlight the possibility of false-negative results with conventional CT in patients with cecal endometriosis. We consider CT colonography with air/carbon dioxide insufflation preferable to conventional CT for tumor detection in patients with cecal lesions identified during colonoscopy.” (emphasis added)

A study published in the February 2021 edition of The American Surgeon reports a 41-year-old woman had a mass nearly blocking her sigmoid colon. A CT scan confirmed the presence of the obstruction. A flexible sigmoidoscopy was attempted, but was unable to breach the obstruction. She underwent a laparotomy where it was discovered that her left ovary and fallopian tube were adhered to her sigmoid colon and surgically removed along with her blocked sigmoid colon. Pathology revealed “extensive” Endometriosis of the colon mass and ovary, as well as adhesions.

The International Surgery Journal published a March 2021 study of 45-year-old woman who had been suspected of peritonitis (inflammation of the peritoneum); she had no prior history of abnormal periods or Endometriosis. A physical examination divulged her rectal cavity was “ballooning and tender…” and a laparotomy was in order. During surgery, they found a perforation in her sigmoid colon, and her abdominal cavity had been contaminated with escaped fecal matter (yes, that’s poop). They also found a “large mass” near the upper portion of her rectum. She received a bowel resection, and a temporary bag, and stayed in the hospital for seven days. Pathology came back that the mass was Endometriosis and it had fully involved the wall of her sigmoid colon, most likely causing the perforation. After three months, the bag-procedure was reversed. During that reversal surgery, they discovered a cyst on her left ovary, but the biopsy came back as NOT Endometriosis. There was no other Endometriosis discovered in her pelvic cavity during both surgeries.

Another March 2021 study was published in the American Journal of Case Reports of a 40-year-old woman who had lower right abdominal pain for years. For several months the pain worsened and also led to nausea and vomiting, so she went to the hospital. A CT scan found a lesion on her small bowel and a narrowing of the bowel as well. A colonoscopy found that the terminal ileum protruded inward (likely due to the lesion). A surgery was performed and a portion of her bowels and appendix were removed. Pathology showed “endometrium-like” tissue had invaded her bowel walls and appendix as well as nearby lymph nodes. Unfortunately, the study does not let us know how she fared after surgery and recovery.

What Now?

If you suspect you may have Endometriosis on or near your bowel, talk to your physician.  Get the ball rolling on diagnostic tests and specialist referrals.  Have patience and an open mind…

Now, if you regularly follow my blogs, you’ll know that I was worried that I may have it on my bowel.  I’ve got the symptoms (all of them except decreased appetite, nausea, and vomiting).  They had disappeared for about a year after my excision surgery, but then since returned.   My excision op report stated, “Cul-de-sac was also obliterated and was massively adhered with adhesions from Endometriosis.”  Of course I was concerned…I visited my gyno, a GI doctor, and a colorectal surgeon to discuss. BUT…without going in surgically to confirm my suspicions, I was taking the “wait and see” approach.  It may be Endo…it may not.  My symptoms improved since the colorectal surgeon ordered me to take fiber…but returned, of course. In July 2018, I underwent another excision surgery due to my returned pain in symptoms. And my surgeon found Endometriosis on my small intestine that was too deep to remove. So, I had another surgery in November 2018 to excise MORE endometriosis and included a resection of 7″ of my guts, including a section of my small intestine, the ileocecal valve, appendix, cecum, a portion of my large intestine; all of which came back as bowel Endometriosis. In May 2020, I had my fifth excision surgery and they found deep-infiltrating Endometriosis on my sigmoid colon. So, in October of 2020, I had my second bowel resection and am feeling much, much better. Yep. I have (had) bowel endometriosis.

Thanks for reading!



*Updated April 14, 2021*


American Cancer Society – Signs and Symptoms of Gastrointestinal Stromal Tumors

American College of Gastroenterology Case Reports JournalPolypoid Endometriosis Presenting as Colonic Mass

American Journal of Case Reports – (Abstract; March 2021) Small Bowel Obstruction Caused by Ileal Endometriosis with Appendiceal and Lymph Node Involvement Treated with Single-Incision Laparoscopic Surgery: A Case Report and Review of the Literature

American Journal of Obstetrics & Gynecology – (Abstract; Dec. 2002) Sigmoid Endometriosis in a Postmenopausal Woman

American Journal of Obstetrics & Gynecology – (Abstract; Feb. 2016) Surgical Treatment of Deep Infiltrating Rectal Endometriosis: In Favor of Less Aggressive Surgery

Annali Italiani di Chirurgia (Abstract; March 2019) Rectal Perforation Caused by Deep Infiltrating Endometriosis in Non-Pregnant Woman: Case Report and Short Review of the Literature

Annals of Surgery – (Article; May 1973) Endometriosis of the Bowel: Role of Bowel Resection, Superficial Excision and Oophorectomy in Treatment

Asian Journal of Endoscopic Surgery – (Abstract; April 2015) Small Bowel Obstruction Caused by Endometriosis in a Postmenopausal Woman

Best Practice & Research Clinical Obstetrics & Gynaecology – (Abstract; Nov. 2015) Bowel Complications in Endometriosis Surgery

Best Practice & Research Clinical Obstetrics & Gynaecology – (Article; June 2020) Advances in the Medical Management of Bowel Endometriosis

BMJ Case Reports – (Abstract; April 2015) Endometriosis Masquerading as Crohn’s Disease in a Patient with Acute Small Bowel Obstruction

Canadian Medical Association Journal – (Article; August 2020) Intestinal Endometriosis in a 36-Year-Old Woman

Case Reports in Medicine – (Article; July 2020) Large Bowel Endometriosis Mimicking Colorectal Cancer

Case Reports in Surgery– (Article; 2019) Endometriosis Mimicking a Cecum Mass with Complete Bowel Obstruction: An Infrequent Cause of Acute Abdomen

Centers for Disease Control and PreventionPelvic Inflammatory Disease

Centre for Advanced Reproductive EndosurgeryBowel Endometriosis

Clinical Medicine Insights Reproductive Health – (Article; Feb. 2016) Relevance of Imaging Examinations in the Surgical Planning of Patients with Bowel Endometriosis

Crohn’s & Colitis Foundation of AmericaWhat is Crohn’s Disease?

Crohn’s & Colitis Foundation of AmericaWhat is Ulcerative Colitis?

Digestive Diseases and Sciences – (Abstract; May 1994) Small Bowel Endometriosis Masquerading as Regional Enteritis

Diseases of the Colon & Rectum – (Abstract; Nov. 2020) Endometriosis of the Bowel

Endometriosis Foundation of America – (video) When IBS is Really Endometriosis on the Bowel

Endometriosis.orgBowel Symptoms

Endometriosis UKEndometriosis and the Bowel

European Journal of Obstetrics & Gynecology and Reproductive Biology – Colorectal Endometriosis and Fertility

Fertility & Sterility – (Abstract; Jan. 2017) Functional Outcomes After Disc Excision in Deep Endometriosis of the Rectum Using Transanal Staplers: A Series of 111 Consecutive Patients

Gastroenterology Research – (Article; Feb. 2017) Colonic Endometriosis: Dig Deeper for Diganosis

Gynecologie Obstetrique & Fertilite– (Abstract; Jan. 2016) Computed Tomography-Based Virtual Colonoscopy in the Assessment of Bowel Endometriosis: the Surgeon’s Point of View

Harvard Health Publications- Diverticulosis and diverticulitis

Human Pathology – (Abstract; Oct. 1994) Mucosal Changes in the Large Bowel with Endometriosis: a Possible Cause of Misdiagnosis of Colitis?

Human Reproduction – (Abstract; Nov. 2003) Preferential Infiltration of Large Bowel Endometriosis Along the Nerves of the Colon

Human Reproduction – (Article; 2010) Transvaginal Ultrasonography with Bowel Preparation is Able to Predict the Number of Lesions and Rectosigmoid Layers Affected in Cases of Deep Endometriosis, Defining Surgical Strategy

International Surgery Journal – (Article; March 2021) A rare presentation of rectal endometriosis

Journal of Surgical Case Reports – (Article; June 2020) A Rare Case of Ielococlic Intussusception due to Severe Endometriosis

International Journal of Colorectal Disease – (Feb. 2016) Letter to the Editor: Recurrent Symptoms of Gastrointestinal Tract Caused by Isolated Endometriosis in a Middle-Aged Female

International Journal of Scientific Research (Article; March 2019) Isolated Recto-Sigmoid Endometriosis Masquerading as Malignancy: Dig Deeper for Diagnosis

International Journal of Surgery Case Reports – (Article, Sept. 2017) A Case Report of Endometriosis Presenting as Acute Small Bowel Obstruction

JAMA Internal Medicine – (Abstract; 1995) Intestinal Endometriosis Masquerading as Common Digestive Disorders

Journal of Minimally Invasive Gynecology – (Abstract; June 2011) Is Pouch of Douglas Obliteration a Marker of Bowel Endometriosis?

Journal of Ultrasound in Medicine – (Abstract; March 2015) Deep Infiltrating Endometriosis of the Bowel Wall

LivestrongGastrointestinal Endometriosis Symptoms

Mount Sinai HospitalIschemic Bowel Disease

National Institute of Diabetes and Digestive and Kidney DiseasesSymptoms and Causes of Appendicitis

Nezhat.orgBowel & Bladder Endometriosis Symptoms

OBGYN.netIntestinal Endometriosis

Pakistan Journal of Medical Sciences – (Article; 2016) Diagnosis and Surgical Treatments of Isolated Rectal Endometriosis: Long Term Complication of Incomplete Treatment for Pelvic Endometriosis

Paripex – Indian Journal of Research – (Article; Jan. 2019) A Case Report of Colonic Endometriosis with Colonic Stricture

Sao Paulo Medical Journal – (Article; July 2008) Epigastric Pain Relating to Menses Can Be a Symptom of Bowel Endometriosis

Society of Laparoendoscopic Surgeons – Laparoscopic Management of Intestinal Endometriosis

Surgical Case Reports – (Article; August 2020) Obstructive Rectal Endometriosis Treated by Robot-Assisted Laparoscopic Surgery: A Case Report

The American Journal of Gastroenterology – (Abstract; Oct. 2020) S1264 Endometriosis of the Colon and Pericolic Lymph Nodes Persenting as Cecal Volvulus: A Case Report

The American Journal of Gastroenterology – (Abstract; Oct. 2020) S2224 An Unusual Case of Hematochezia Secondary to Isolated Recto-Sigmoid Endometriosis Mimicking a Tumor

The American Journal of Gastroenterology – (Abstract; Oct. 2020) S2263 A Case of Small Bowel Endometriosis

The American Surgeon – (Abstract; Feb. 2021) Endometrioma Causing Near-Complete Obstruction of the Sigmoid Colon

The Japanese Society of Internal Medicine – (Article; Dec. 2020) Two Cases of Endometriosis in the Cecum Detected by Contrast-enhanced Computed Tomography with Air/Carbon Dioxide Insufflation

The Kaohsiung Journal of Medical Sciences – (Article; Jan. 2018) Endometriosis, an Unusual Case of Rectal Mass with Bloody Stool and Bowel Habit Changes

The Obstetrician and Gynecologist – (Article; Jan. 2016) Endometriosis and Irritable Bowel Syndrome: a Dilemma for the Gynaecologist and Gastroenterologist

Turkish Society of Colon and Rectal Surgery – (Article; 2020) Mechanical Small Bowel Obstruction Due to Ileal Endometriosis

Ultrasound in Obstetrics & Gynecology – (Article; Feb. 2011) Diagnostic Accuracy of Transvaginal Ultrasound for Non-Invasive Diagnosis of Bowel Endometriosis: Systematic Review and Meta-Analysis

Ultrasound in Obstetrics & Gynecology – (Letter to Editor; April 2017) Transrectal High-Intensity Focused Ultrasound as Focal Therapy for Posterior Deep Invasive Endometriosis

University of Pelita Harapan – (Article; June 2020) Case Report: Caecal Endometriosis is Causing Acute Small Bowel Obstruction

World Journal of Gastroenterology – (Article; Nov. 2014) Bowel Endometriosis: Colorectal Surgeon’s Perspective in a Multidisciplinary Surgical Team

World Journal of Gastroenterology – (Article; Dec. 2015) Colorectal Resection in Deep Pelvic Endometriosis: Surgical Technique and Post-Operative Complications

World Journal of Gastroenterology– (Article; April 2015) Role of Colonoscopy in the Diagnostic Work-Up of Bowel Endometriosis

~ Again, I am a layman.  I do not hold any college degrees, nor mastery of knowledge.  Please take what I say with a grain of salt.  If curious, do your own research 😉 Validate my writings.  Or challenge them.  And ALWAYS feel free to consult with your physician. Always.  Yours ~ Lisa

31 thoughts on “Endometriosis & The Bowel

  1. Fantastic post! So glad to know I am not alone with these symptoms. I actually learned more from this post than from my own research *and* chatting with some doctors.

    Liked by 1 person

    1. ❤ I'm so glad it was helpful, Toni! Looking forward to meeting you! And these symptoms always come up at our support group meetings; nope – you're not alone in these symptoms. Not one bit. 😉


  2. Hi Lisa, when I first had my endo surgery back in 1995 my gyno said it was also on the outside of my bowel and that he didn’t take a lot of it off as he didn’t want to damage my bowel. I have had a lot of bowel problems over the years and had 2 colonoscopies which they found polyps, but still the symptoms as you have listed have remained. I am booked in to see a gyno next week to discuss my endo and will definately be mentioning the bowel problems too. Thanks do much for the information. Have a great day, Dayna

    Liked by 1 person

    1. Dayna, you’re SO welcome! Good luck with the discussion with your gyno! Keep us posted. My gyno, the GI, and the colorectal surgeon all agreed that my symptoms *could* be Endo on the bowels, but without surgery, we can’t confirm it. My next gyno appointment is in April and after researching today I’m going to be asking for another transvaginal ultrasound. I haven’t had one in over a year and with the return of my symptoms, I’d like one. 🙂 We can be our own advocate. And I’m proud of you for deciding to talk to yours further 🙂

      Liked by 1 person

  3. Even before being diagnosed with endo through laparascopy, I had issues with bowel/rectal pain during my period. The lap confirmed adhesions on my bowel. Things got better after most of the adhesions were removed, and then I got pregnant 2 years later and had a 2 year respite from good old Aunt Flow. Alas, the pain is back. 😦 I’m one of the lucky ones who has pain only during my period (pain, constipation, and bleeding), so once we’re done building our family, I will talk to my OB about a permanent ban on my period.

    Liked by 1 person

  4. “permanent ban on my period” – haha. Here’s to hoping it helps – well, it will definitely help with the period pain. 🙂 And I’m SO glad you’re able to build a family!!


  5. I have a sister who had severe endometriosis and a hysterectomy. Now I have been struggling with frequent bouts of diverticulitis and rounds of antibiotics. But each bout of diverticulitis brings on horrible pain, not only in the colon but in the area of my uterus. Along with the usual diverticulitis sx. I have always had horrible periods, pain and heavy bleeding. I have an appointment in the next month with my gyn and look forward to asking about this.
    Thanks so much for your post. Maybe it is time to stop seeing these things in isolation.

    Liked by 1 person

  6. Thanks so much for this info Lisa. My daughter has had continual diarrhea for nearly a year. It started 7 months after she delivered her first baby; her periods resumed a few weeks after that. She has always had very painful periods but has never officially been diagnosed with endometriosis.
    In investigating her diarrhea, she was found to have an intestinal parasite but several rounds of antibiotics have not cleared it and the diarrhea continues. Her doctor is looking for other causes and she will have a colonoscopy soon.
    The doctor didn’t consider bowel endometriosis because “she has the diarrhea throughout the month not just during her period”. From my reading I understand there is a possibility that diarrhea may be constant with endometriosis, not just cyclical.
    In your understanding of bowel endometriosis is this a possibility? If so, we will encourage my daughter’s dr to not automatically dismiss it as a possible cause.
    Thank you so much for your help Lisa.


    1. It could be. But it could also be many other things. I glad go hear she has a colonoscopy scheduled; pursue every avenue. But, correct, Endometriosis pain any symptoms may not stick with the monthly flow. Many women suffer Symptoms often and some women…always. wishing your daughter the best of luck! And you strength.


    2. I was wondering what your daughters results were, seeing as I have had the same issue with several rounds of antibiotics not helping my ‘intestinal parasite’, and have always had horrible periods, with cramps that could knock me to my knees, including hospital visits because of them, stomach issues through out the entire month, constant bloating, and every other symptom mentioned, for as long as I can remember for most of my life since I started getting periods. My doctors continuously brush off endometriosis, and are set on it being an intestinal parasite! Either way, I feel her pain and hope she is doing better, with a better diagnosis.


  7. Thank you so much for this article!
    I had my hysterectomy in July after years of increasingly worrisome symptoms that ranged from abdominal pain, fatigue, diarrhea, and of course extremely heavy periods (10-12 days total). Initially, I was diagnosed as extremely anemic, my general practitioner then sent me to my gyno. Found out that I have what I affectionately refer to as an over achieving uterus (enlarged) which attributed to the anemia, and received iron infusions due to how low my blood iron was. Also, via ultra sound, found that I had a very large fibroid. Due to the size of the fibroid and that it had started to calcify, as well as the size of my uterus, it was determined to perform open abdominal surgery. During surgery, my doctor found that at some point, I had suffered from endo. My right ovary was fused to my uterus, and my cervix had adhered to my rectum. I was initially going to keep my ovaries, so I still have the left ovary. The surgeon called in a colorectal surgeon, and they together determined it best to leave my uterus as they did not think I needed to receive a colostomy bag. (I still am thankful they made that call) They removed as much of tissue as they could, leaving my good ol cervix behind. I can’t believe how much better I feel. After reading your article, I feel I’m better equipped in case I have further issues. Thank you thank you thank you thank you!

    Liked by 1 person

  8. I have all the horrible bowel symptoms you mention. I had a laugh 3 years ago but it was just under a regular gynecologist and he claimed it was not on my bowels. I’m so terrified of it being on my bowels and Perforating my colon or something like that… It’s to the point where I get super nauseous and Bloated and gassy and such right before and right after period.


  9. I have all the symptoms you mentioned and I am absolutely terrified of my bowel Perforating. I had a lap three years ago with a regular GYN and he claimed it was not on my bowel. Although lately my symptoms are getting worse and I’m even getting very nauseous right before my period. I’m scheduled to see an excision specialist but I really don’t want my bowels worked on. Wondering if diet can help? I’m just not sure what else to do. Thank you for your information!

    Liked by 1 person

    1. Hey melody. I have Endo on my bowel, and post surgery, I was put on the FODMAP diet, to basically see what was triggering my bowel and causing issues. I highly reccommend giving it a go. its super hard, but worth it!


  10. Thanks for this post, Lisa- it was super informative and a good reminder of a few things for me. Lucky me! I am in that 5-15% of women who have endo on my bowel. It was adhering my abdominal wall to the outside of my bowel, so that was a nicely uncomfortable surgery to go through. Since this surgery, a few things have happened as far as treatment goes, and i know everyone is different, but these have been super helpful for me:

    I started on the FODMAp diet to find out if aside from my endo, there were any other contributing factors to inflammation and BINGO! turns out Gluten and lentils are a killer. Not only do both f these cause me extreme bloating and lower back pain (feels like I have been booted i the lower spine/between my hips), I also get extreme fatigue to the point where I can sleep 20 out of 2 hours a day, for 3-4 days on end. My body didn’t know what hit it when I cut these things out and then reintroduced them- it was a big NO-No. So now i just steer clear as much as possible.
    The second thing that has been extremely helpful, was starting on some nerve blocking medication (which also, coincidentally, helps with my anxiety). I take Duloxetine once a day, and man oh man, aside from the first month where I was a bit nauseous taking it, now, my pain on a daily basis has gone from a contiual 7 or 8 down to a 2 or 3 (unless im in a flare up).

    the biggest and scariest thing for me right now, is getting educated and informed about my fertility options. As bowel Endo is stage 4, my chances of being able to fall pregnant and stay that way are very slim, so right now im eating as healthily as possible, listening to my body, exercising, resting, and generally just putting my health first.

    Urrrgghh this stupid illness is the pits. But thank you for doing what you’re doing!



  11. Having doctors believe something is wrong with you is hard enough…having doctors believe you are having cyclic rectal bleeding when you have no ovaries and are not on HRT…down right Impossible!!! Have seen numerous doctors and not one of them believe what I am telling them. Also note that this rectal bleeding has caused me to be anemic and have horrible anemia symptoms and pain, along with the rectal bleeding which arrives like clockwork. Additionally, had TAH with removal of my ovaries…had deep infiltrating endometriosis and adhesions. Cannot find any real medical research on this either…only other women’s personal experiences. Was feeling good for about 6-8 months, then started having low-back pain which has turned into excruciating back pain and now many other endometriosis symptoms have started to pop up again. I know endometriosis can return and return with a vengeance, but this is awful. Plus with all of this…quality of life has gone downhill, have become a recluse other than work, which is becoming more and more of a challenge to do. So much more I could share, but trying to make this short, sweet and to the point. Thanks for listening.


    1. Please do talk to your physician. I have a few studies here…one about a woman who bled from her bum even after a hysterectomy. Let me know if you’re interested and I’ll find the link and post it here. Arm yourself with studies…then demand they consider it. ❤


  12. Thank you so much for sharing this. I expect there to be bowel endometriosis for me too. Two of my gynecologist surgeons previously were only to look in “their” specialty area. I am meeting with a third soon who works with her GI husband and his team. How awesome is that!? I’ve got to explain all of my history and symptoms and hopefully get a real big surgery done! Yikes and yay!

    Liked by 1 person

    1. I am so excited for you! My May 13th surgery revealed I have deep infiltrating endometriosis on my sigmoid colonnd I have a consultation with my colorectal surgeon on Tuesday. I’m very excited for you and the pending surgery and hopeful long-lasting relief!


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