Intestinal Endometriosis

Most patients with endometriosis do not have intestinal (GI) involvement. Among the difficult cases of endometriosis I see from around the world, only 27% have GI involvement. Since over 1900 patients with endometriosis have undergone surgery at St. Charles, that means I’ve operated on over 500 patients with GI involvement. 

The symptoms of GI involvement depend on the severity and location of the disease. The severity of disease depends on the depth of invasion into the bowel wall. 

When endometriosis invades the bowel wall deeply, it causes a lot of scarring and retraction and can form a tumor which partially obstructs the bowel wall. When disease is very superficial, it usually causes no symptoms at all. There is a long continuum of disease severity from very superficial to very bulky and invasive, and some patients can have both superficial disease in one area of the bowel, and bulky invasive disease in another.

The location of GI endometriosis follows well-defined patterns. The lower rectosigmoid colon is most commonly involved, followed by the last part of the ileum (the small intestine), the cecum (the first part of the large bowel), and the appendix (which hangs off of the cecum). Thirty percent of patients have more than one GI area involved. Superficial disease in any of these areas usually causes no symptoms, but bulky, deeply invasive disease can cause real problems.

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.

Interestingly, although you might think vaginal endometriosis would be obvious on speculum exam in the office, it is usually missed because most physicians don’t think to look just behind the cervix; they are more intent on seeing the cervix so they can do a PAP smear. Frequently the doctor may be able to feel nodularity behind the cervix on exam, and this area can be very painful.


A rectal nodule with obliteration of the cul de sac can cause painful bowel movements all month long, rectal pain during intercourse or while sitting, and rectal pain with passing gas. It can also cause constipation, although diarrhea can be present during the menstrual flow. When the sigmoid colon is involved by bulky disease, patients can have constipation alternating with diarrhea and intestinal bloating and cramping. Bulky endometriosis invading the ileum can result in right lower quadrant pain, bloating, and intestinal cramping. Disease of the cecum and appendix usually causes no specific symptoms at all. Most patients with GI endometriosis do not have rectal bleeding, although when rectal bleeding and painful symptoms occur during the menstrual flow, this raises suspicion for GI involvement.

GI x-rays and colonoscopy are rarely useful in diagnosing GI endometriosis because the disease usually doesn’t penetrate all the way through the bowel, but remains in the muscular wall of the bowel. Most patients will have negative GI workups, and GI endometriosis requires surgery for its diagnosis. Laparoscopy is adequate for diagnosing GI disease provided that the surgeon takes the effort to look at the areas which can be involved and also knows what GI disease can look like (it’s most commonly white because of scarring surrounding the disease). Most gynecologists do not look at the intestines very closely, so many laparoscopies are useless for ruling out GI disease.

Looking at GI endometriosis will not make it go away, and now the question about treatment comes up. Fortunately, this is a simple topic. Medical therapy has never been studied with respect to intestinal endometriosis. Medical therapy does not eradicate endometriosis of any stage or location anyway and is not FDA-approved for treating infertility associated with endometriosis. The only indication for medical therapy in treating endometriosis of the pelvis or GI tract is to attempt to achieve temporary pain relief if the patient must wait a long time for surgery. Surgery is the only way to eradicate GI endometriosis. Many patients who have had GI disease diagnosed have hysterectomy and removal of the ovaries recommended to them, even though these organs may be
uninvolved by disease.

While it is true that depriving the patient of estrogen stimulation of endometriosis by such surgery will often reduce or eliminate pain, it makes much more sense in many patients to remove the disease first and see what that does for pain. If the uterus is causing problems because of fibroid tumors or adenomyosis, and if the patient has completed her childbearing career and simply is tired of putting up with pain and repeated surgeries, then removal of the pelvic organs may add to the relief of removing all endometriosis. However, it is rarely necessary to consider removal of the uterus, tubes and ovaries to treat pelvic or GI endometriosis since removing those organs doesn’t eradicate the disease. While many surgeons like to use laser vaporization or electrocoagulation to treat pelvic endometriosis, it is unsafe to burn at the bowel (although some surgeons occasionally do this) because a hole could be created which is not obvious and which can cause serious complications. Excision of the endometriosis with suture or staple repair of the bowel wall is necessary to safely and completely remove GI disease.


At St. Charles, we have pioneered surgical treatment of GI endometriosis, and it is now possible to treat most cases of GI involvement with the laparoscope. Most patients do not require a segmental bowel resection where the diseased segment is removed and the 2 ends of the bowel are put back together. Even if this is necessary, laparotomy is not always required. 

In a new twist for those who do require laparotomy, I have found that if the laparoscope is used to treat all pelvic disease and then to isolate the segment of bowel to be removed, that the incision can be kept quite small.

One patient recently had full thickness resection and repair of a rectal nodule, but I also saw nodular disease of her sigmoid and ileum. By isolating the sigmoid nodule laparoscopically, I was able to make a small 3 inch incision and we were able to do segmental bowel resections on both the ileum and sigmoid through this tiny incision. The patient was dreading seeing her incision, but when I took the dressing off two days later, she looked at it and said "That’s not so bad. I can still wear my bikini."

Colostomy is not necessary in any patient to treat GI endometriosis. We have had only one serious complication in over 500 patients. A patient developed a leak from her suture line a few days after surgery and required a temporary colostomy for healing. This has since been reversed and she is having normal bowel movements once again. Another patient developed a stricture requiring dilation of the bowel.

To our knowledge, the endometriosis treatment team at St. Charles has more experience than any center in the world in treating GI involvement. I personally do most of the bowel surgery and enlist the aid of Dr. Dean Sharpe or Dr. Marinus Koning when the occasional segmental bowel resection is necessary. GI endometriosis doesn’t need to be frightening or mysterious. Like pelvic endometriosis, it is actually straightforward when the disease is understood. Doctors sometimes tend to make things sound more complicated than they really are because they may not have much experience treating endometriosis.