Monthly Column By Dr. Andrew Cook
This Month's Topic:
Bowel Endometriosis
ENDOMETRIOSIS OF THE BOWEL
Endometriosis has been reported to grow in almost every organ in the body outside of the reproductive organs. The
bowel is the most common non reproductive organ involved with endometriosis.
BOWEL ANATOMY 101
The intestines (bowel) are made up of two basic parts, the small intestine and the large intestine. The small intestine
is about 9 feet long and the large intestine is about 3.5 feet long. The small intestine connects the stomach to
the large intestine. The small intestine fills the area from the from the bottom of the ribs to the top of the
uterus. It has no set course and looks a bit like a bunch a spaghetti. The large intestine connects the small intestine
to the anus. From the anus the large intestine follows a course behind the vagina, cervix and uterus, and makes
an upside down "U", up the left side of the body, across the upper abdomen just below the ribs and down
the right side of the abdomen ending near the hip bone on the right. The appendix is a small worm like structure
projecting off of the large intestine close to where the large and small bowel connect. The contents of the small
bowel are primarily liquid while those of the large bowel are primarily solid. The bowel wall is made up of three
basic layers; (1) the serosa, (2) the muscle wall and (3) the mucosa. The serosa is outside lining of the bowel
wall. It is very thin, similar to saran wrap. Most of the bowel wall is made up of muscle. This is the middle layer.
The inside lining of the bowel is called the mucosa and is also quite thin.
INVASION
The degree of invasion of the bowel wall by endometriosis is one factor that will determine the type of symptoms
that the patient will experience. If the bowel endometriosis is superficial, involving only the outside serosal
surface, the most common symptoms are bloating, nausea and loose stools with menses. At the other extreme, if the
endometriosis has invaded all the way through the bowel wall including the inside mucosa, then the patient will
usually experience rectal bleeding with her period. While it is common for the endometriosis to invade through
the outside serosa and the middle muscle wall, it is unusual to invade through the inner mucosal layer. This probably
accounts for the high failure rate of barium enemas and colonoscopsies in diagnosing bowel endometriosis. The location
of the bowel will be the primary determining factor of the type of symptoms when the muscle wall of the bowel is
involved with endometriosis.
LARGE BOWEL
The pelvic portion of the large bowel (the rectum and the sigmoid colon) is the most commonly involved part of
the intestine. The close proximity of this portion of the bowel to the vagina and cervix often results in painful
intercourse. Bowl movements can also be very painful since the bowel contents are solid in this portion of the
bowel. The portion of the intestine where the large and small bowel connect is located in the area between the
belly button and the right hip bone. This is in the same area as the appendix. Involvement of the bowel in this
area or the appendix can result in right sided pain. Bowel endometriosis can also result in adhesions (scar tissue).
These adhesions can involve other loops of bowel resulting in a partial obstruction (blockage), the ovary, fallopian
tube or even the ureter. These adhesions can also result in pain. Endometriosis of the large bowel rarely results
in obstruction of the bowel.
SMALL BOWEL
Endometriosis of the small bowel usually results in bloating and pain which is associated with eating. Often patients
with small bowel endometriosis have restricted the amount and type of foods that they eat. The symptoms are slowly
progressive over time and the patient may not even realize the extent to which she has altered her diet. Small
bowel endometriosis often results in a partial bowel obstruction. As the bowel swells following a meal the bowel
kinks, and like a kinked garden hose the contents do not get through until enough pressure builds up to push by
the narrowed portion.
TREATMENT OF BOWEL ENDOMETRIOSIS
All of my patients undergoing surgery have a preoperative bowel preparation. It is impossible to tell preoperatively
if bowel endometriosis is present. I find that the laser is a wonderful surgical instrument for treating bowel
endometriosis. This provides the precision necessary for me to remove the endometriosis from the bowel, without
having to perform a bowel resection in the vast majority of cases. Situations in which electrosurgery could result
in the need for bowel resection are, I fell better handled by laser surgery. This is true for both the large and
small bowel. In the rare cases that the endometriosis has completely replaced a section of bowel, the diseased
segment of bowel is removed by one of the bowel surgeons of my team and the normal ends of the bowel are reconnected.
NON SURGICAL TREATMENT OF BOWEL ENDOMETRIOSIS
At this point in time there is no non surgical treatment of bowel endometriosis. Lupron, birth control pills etc,
may slow the growth of endometriosis, but they will not get rid of the endometriosis nor the associated fibrosis
or adhesions. Invasive bowel endometriosis is a serious condition which can lead to an acute surgical emergency
(bowel obstruction).
THE TEAM APPROACH TO THE TREATMENT OF ENDOMETRIOSIS
Endometriosis is a dreaded disease which has no respect for the boundaries of the various medical subspecialties.
This is why it is so important to use a team approach in the treatment of individuals with endometriosis.
In cases were the endometriosis involves the full thickness of the bowel, a surgeon should be available to perform
a segmental bowel resection and reanastomosis at the time the patient is undergoing treatment of her endometriosis
by her gynecologist. Proper preoperative evaluation and preparation in conjunction with the team approach should
result in the complete treatment of the individual with endometriosis.
This page and all of the contents are Copyright © 1998 by Andrew Cook, M.D.
The information contained on this web page is considered informational and is not intended as medical advise. You should seek the advise and care of your local physician. Information on this web site is subject to change without any notice. The information on this web page may include technical inaccuracies or typographical errors.