What is an Ileo-Anal Pouch?

An ileo-anal pouch is an internal pouch that is formed during a surgical procedure and which serves as a reservoir for waste. In a procedure performed on people who have chronic large intestine disease or colon cancer, the pouch is formed from loops of the small intestine. An ileo-anal pouch also is called an ileal pouch-anal anastomosis, ileal-anal pullthrough or j-pouch.

Some digestive system diseases can cause severe damage to the large intestine, which includes the colon. For example, the chronic inflammatories diseases ulcerative colitis and Crohn’s disease can cause massive damage to the colon. In cases of very severe damage, the best course of treatment is sometimes to remove most or all of the colon. This is carried out to prevent further damage and to prevent potentially fatal complications such as the massive colon swelling known as toxic megacolon.

In a surgical procedure called a proctocolectomy, the colon is removed, and a pouch is constructed from a section of the small intestine. To create the pouch, several small loops of small intestine are folded and stitched together. Next, the pouch itself is constructed by removing the inside walls of the folds of small intestine. Finally, the new pouch is stitched in place in the lower peritoneal cavity.

The newly created ileo-anal pouch needs several weeks to heal before it can safely process food. To allow time for the pouch to heal, the surgeon will create a temporary ileostomy. This involves creating a hole called a stoma in the abdominal wall and attaching the end of the small intestine to this hole. When food is eaten, it is processed into stool in the stomach and small intestine. Stool then feeds through the stoma and into an external reservoir, thus bypassing the internal pouch. After approximately two months, the patient will undergo another surgical procedure, during which the ileostomy is removed.

People who undergo this series of surgical procedures will find that their bowel habits change significantly. The main reason for this is that the ileo-anal pouch is a relatively small reservoir, in comparison to the large intestine. Another reason is that most of the water in liquid stool is reabsorbed by the body as the stool passes through the colon. In someone who has had a proctocolectomy, stool passes through the body more quickly and contains much more liquid. Another potential problem is reduced absorption of gastric acid in the pouch, which can cause anal burning.

To prevent dehydration caused by increased loss of water in stool, people who have an ileo-anal pouch must keep fluid intake high. Salt deficiency also is a possibility because of the increased water loss. To combat these problems, many people add more salt when cooking and use electrolyte drinks in cases of severe or chronic dehydration.

Eating a low-fiber diet can help reduce stool output after surgery. One way to accomplish this is by eating white breads, rice and cereals rather than whole grains. This helps absorb odors, thicken the stool, reduce frequency of bowel movements, and reduce dehydration and anal burning.