Endometriosis and Bowel Symptoms
Endometriosis and Bowel Symptoms
Endometriosis Editorial Advisory
Ken Sinervo MD
for Endometriosis Care
Many of the women seen at the Center for Endometriosis Care have
been told they have Irritable Bowel Syndrome or a spastic colon. A
few of them do. But many of them have endometriosis somewhere in
their intestinal tracts.
Endometriosis patients who present with bowel symptoms may
experience a long delay in getting a diagnosis or have other medical
conditions related to the bowel considered before their physicians
consider the possibility of endometriosis.
Bowel symptoms are extremely common in patients with endometriosis.
While the exact percentage of endometriosis patients affected with
bowel symptoms is difficult to pin down, information from the
database Dr. Albee and I have compiled suggests that as many as 60%
or more may have at least one symptom referable to their
gastrointestinal tracts. Because of the nature of our practice we
tend to have more patients with stage III and IV (moderate to
severe) disease than may occur in the general population. Such
patients may have more symptoms related to their bowels. Even so,
the incidence is still very high.
Based on the pre-operative questionnaires that all of our patients
complete, intestinal cramping and painful bowel movements occur in
approximately 25% of patients; constipation occurs in 35% of
patients and diarrhea occurs in more than 60% of patients. These
numbers reflect the patients with severe or crippling symptoms only.
When patients with mild or moderate symptoms are included, these
symptoms become even more common.
There is a constellation of bowel symptoms that can occur in
endometriosis patients. These include:
- Painful bowel movements
- Alternating constipation and diarrhea
- Intestinal cramping
- Nausea and/or vomiting
- Abdominal pain
- Rectal pain
- Rectal bleeding
Some patients will only have one of these symptoms, while others
may have all of them. Often these symptoms are more problematic
during their periods or pre-menstrually. These women may seek
medical help and undergo a series of GI tests, and when no clear
answer is found, their frustration grows. However, a negative
colonoscopy can actually be somewhat reassuring, because it
indicates that endometriosis has not penetrated through the wall of
What Causes Bowel Symptoms in Endo Patients?
In the great majority of patients, endometriosis is not found
directly on the bowel. In general, fewer than 10-15% of patients
actually have endometriosis directly on their bowel. When endo is
found on the bowel, approximately 90% have superficial or localized
disease. This disease can usually be effectively removed with simple
laparoscopic excision, much as it would be removed from any other
surface affected with endometriosis. The serosal or outer layer of
the bowel can often be “peeled off” leaving the muscularis or
muscular portion of the bowel undamaged. Occasionally, a portion of
the muscularis must also be excised to ensure complete treatment of
the endo. In these cases, the muscularis is oversewn
laparoscopically. This just means one or more reinforcing sutures
are placed to maintain the integrity of the bowel wall.
One to two percent of our patients require more significant surgery
for their bowel endometriosis. These patients may have large
segments of bowel involved with deeper or multi-focal implants
(several areas are affected along a portion of the bowel). A
segmental bowel resection may be required to completely treat their
disease. This means the diseased portion of the bowel is removed
entirely, and the healthy ends are reconnected. These procedures are
usually performed with the assistance of a general surgeon or
colorectal surgeon, and virtually always laparoscopically.
Even when endometriosis does not occur directly on the bowel, it can
cause bowel symptoms. Inflammatory mediators can affect the bowel
and contribute to them. Inflammatory mediators are released by
tissues in response to inflammation or injury, and include
prostaglandins, tumor necrosis factor (TNF), interleukins and
cytokines. They create changes within the tissues and can cause new
blood vessel growth, attract other things to the area such as white
blood cells or contribute to scarring. Prostaglandins, which are
released from the endometriosis implants and uterus during menses,
can cause smooth muscle contractility. This not only affects the
uterus, but can also cause increased contractility of the bowel. In
these cases, diarrhea and intestinal cramping can result. There are
likely other mediators that are released that can also contribute to
This is an invasive nodule of the sigmoid.
Occasionally, deep implants in adjacent structures such as the
uterosacral ligaments or rectovaginal septum can also cause bowel
symptoms. Painful bowel movements and occasionally rectal bleeding
can result from endometriosis in these locations.
The Dreaded Bowel Prep
In order to have these procedures at the time of surgery, most
of our patients undergo a bowel prep. While this is not the most
enjoyable way to spend the afternoon before surgery, it is worth
enduring to get to the desired result of completely removing all the
endometriosis. The prep is usually clear liquids and an agent to
thoroughly clean out the bowel. If a prep were not performed, bowel
surgery becomes extremely risky, because fecal matter could spill
and put the patient at high risk for serious infection. If a prep is
not done, and bowel surgery is needed, a second surgical procedure
would be required at a later date.
Here are some tips for
surviving the prep.
Other Causes for Bowel Symptoms
While endometriosis can cause or contribute to bowel symptoms,
there are other important causes of bowel symptoms. Inflammatory
Bowel Disease (IBD), or Crohn’s Disease and Ulcerative Colitis can
be seen. As many as 8% of endometriosis patients with bowel symptoms
may eventually be diagnosed with inflammatory bowel disease. IBD is
usually characterized by abdominal pain, constipation, diarrhea, or
alternating bouts of constipation and diarrhea as well as intestinal
cramping. Patients with Crohn’s Disease may also have mouth ulcers,
fatigue, anemia and hemorrhoids. Rarely, patients can have abscesses
or bowel obstruction. A colonoscopy is usually required to confirm
the diagnosis. IBD is usually treated with medical therapy that aims
to keep the disease in remission or to treat flare ups.
Occasionally, surgery is required for complications such as bowel
obstruction or abscesses.
Women with symptoms similar to those of IBD but without any
abnormalities on colonoscopy are often diagnosed with Irritable
Bowel Syndrome (IBS). IBS is usually treated with dietary changes to
avoid food triggers, and increasing dietary fiber. In some patients,
stress can be a trigger. Avoiding stress or learning to deal more
effectively with stress may help reduce the number of episodes.
Exercise is beneficial for many patients. Medications are necessary
for some patients. These may include anti-depressants, anti-spasmodics
and other medications. In addition, medications that work better for
patients with predominantly diarrhea or constipation are also
available and have been shown to be beneficial for some, but not all
Adhesions can also cause or contribute to bowel symptoms (as well as
other symptoms associated with endometriosis). Often the bowel is
stuck to other structures such as the ovaries, uterus or pelvic
sidewall. This scarring can lead to pain during bowel movements or
constipation or diarrhea. Abdominal bloating is also associated with
adhesive disease, and carefully treating the adhesions may help
reduce many of these symptoms.
What about the Appendix?
The appendix is another gastrointestinal organ that may
contribute to bowel symptoms, or abdominal or pelvic pain. Some
studies have demonstrated endometriosis in up to 20% of appendices.
Although endometriosis may not be present, other conditions such as
scarring or fibrosis may be found, as well as acute or chronic
appendicitis, and even carcinoid tumors (a form of cancer) have been
found in appendices that have been removed. We are more likely to
recommend removal of the appendix if the patient has a history of
right lower quadrant pain. However, if the appendix appears to have
pathology at the time of surgery, it can usually be removed with
minimal additional risk of complication and usually only adds a few
minutes to the surgery. When required, appendectomy can almost
always be performed laparoscopically.
Will My Symptoms Improve?
The incidence of bowel symptoms does improve significantly after
excision surgery for endometriosis. Based on the post-operative
follow-up questionnaires that our patients complete yearly, there is
an 80% reduction in most bowel symptoms. Of the more than 1000
patients in our database, only 3 to 7% continue to have more severe
episodes of painful bowel movements, constipation or intestinal
cramping. Diarrhea, which was present in 63% of our endometriosis
patients, is only significant in 13% following surgery.
While most patients have improvement in their bowel symptoms
following excision surgery for their endometriosis, some will have a
persistence of these symptoms. This may be due to another underlying
medical condition (IBD or IBS). In those patients in whom a work-up
has not been performed, it may be indicated at this time. Blood
tests that detect antibodies associated with IBD may be helpful.
Often a colonoscopy or other studies are required.
Many gynecologists have little or no experience treating bowel
endometriosis. They choose not to treat it. Sometimes they refer
these patients to a general surgeon for later treatment. At the CEC,
these procedures can almost always be performed laparoscopically. It
is worthwhile to ask your doctor how he or she would deal with
endometriosis if it were found on your bowel. If you are not
satisfied with the answers, keep searching until you find the right
person to work with.