In some cases of colorectal disease, such as chronic colitis, colon cancer, or familial adenomatous polyposis (an unusually large number of polyps in the colon), the colon (large intestine) and rectum must be removed using a procedure called a total proctocolectomy.
After removal of these organs, which store and eliminate solid wastes, these patients usually have an ileal pouch-anal anastomosis (IPAA) to provide a new way to store and pass stools.
The term “anastomosis” means a joining together of disconnected parts. In the case of an IPAA, the ileum (lowest part of the small intestine) is formed into a reservoir to store solid wastes. This reservoir or pouch is connected to the anal canal to provide for elimination. The pouch enables the patient to store and pass stool through the body’s usual route, so that the patient doesn’t need an external bag to collect waste.
There are four different types of ileal pouches: J-pouch, S-pouch, W-pouch, and the K-pouch (so named because they resemble the letters).
In order to have an ileal pouch procedure, the patient’s intestinal muscles, sphincter, nerves, and anus must still be able to function normally. This will allow the person to maintain control of bowel movements once a pouch is constructed.
How are the different types of pouch surgeries performed?
A J-pouch is made by using two loops of small intestine, each measuring about six inches long. The pouch is connected to the top of the anal canal in an area called the anal transition zone to allow for elimination of waste matter. After the pouch is constructed, it can hold about two-thirds of a pint of fluid.
The J-pouch is the type that is used most often because it requires the shortest length of intestine, is the easiest of the pouches to make, and is highly efficient.
J-pouch procedures are the preferred method for treating chronic ulcerative colitis in which symptoms are hard to control. J-pouches are also used in cases of familial adenomatous polyposis, and sometimes for colon and rectal cancers.
K-Pouch (also known as a Kock Pouch)
The K-pouch or Kock pouch is used in cases of ulcerative colitis when the large intestine and rectum need to be removed because of disease, and the anal sphincter muscles are weak.
About 20-22 inches of the last portion of the small intestine are used to build an internal reservoir, which is then attached to the inside of the abdominal wall. A small opening (stoma) leads out and is used to drain waste matter through a catheter several times a day.
Three loops of the small intestine, each about six inches in length, are stitched or stapled together to form the pouch. Another length of intestine, approximately six inches, is used to make a valve or “nipple” between the stoma and the pouch. The nipple acts as a flap valve to keep feces and gas inside the pouch until it can be drained. When stool and gas build up inside the pouch, the flap is pushed shut to prevent leakage.
The S-pouch is made the same way as the K-pouch, except without the nipple valve. Instead of a valve, the pouch is attached to the anal canal using the same technique as the J-pouch.
Three loops of small intestine, each about five to six inches in length, are used to make the S-pouch. The pouch is able to hold from one-half pint to a one pint of fluid.
Because the S-pouch is formed with three loops of small bowel, it is bulkier than the J-pouch. Therefore, the S-pouch is generally not used in patients with a small or narrow pelvis.
Approximately half of the patients who have the S-pouch procedure have trouble completely emptying the pouch. These patients have to clear the pouch with intubation (inserting a tube into the pouch).
The W-pouch is constructed using four loops of small intestine. It is sometimes used when the patient has another pouch that needs revision. Patients who have the W-pouch do not need intubation, and often have to go to the bathroom less frequently.
One disadvantage of the W-pouch is that it is bulky, which may make it more difficult to use in patients with a narrow pelvis.
What can be expected after ileal pouch surgery?
After ileal pouch surgery, the patient must have an examination of the inside of the pouch using an instrument called an endoscope every year. If necessary, biopsies of the anal transition zone are recommended to make sure that the disease does not return, and to watch for the development of precancerous cells.
In addition, all types of pouches can develop pouchitis, an irritation and inflammation of the inner lining of the pouch.
There is a 5-7% chance of failure after pouch surgery. Most failures are due to the wrong diagnosis (for example, constructing a pouch in cases of Crohn’s disease), persistent pouchitis, or complications of surgery.
In most cases, quality of life improves over time. Patients can usually resume normal work and activities about 4-8 weeks after surgery.
In some cases, the pouch may need to be repaired or removed and replaced with a new pouch. Another option is to convert the pouch to a permanent ileostomy (an opening through the abdominal wall to evacuate waste).
When is an ileal pouch not recommended?
People in the following situations or who have these conditions may not be good candidates for ileal pouch surgery:
- Crohn’s disease – This inflammatory condition of the entire digestive tract has a high risk of returning after treatment. Therefore, it is not a good idea to use the small intestine to construct a pouch.
- Anal incontinence –problems controlling rectal functions
- Older age – Although a number of elderly patients do well with an ileal pouch, the ideal age range for this surgery is 20-50 years old, when anal sphincter control is at its best.
- Obesity – People who are morbidly obese are not good candidates because of the greater chance of surgical complications, and a thick abdominal wall that makes the procedure more difficult to perform.
This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 7/23/2014...#15549