Why it's done

Ileoanal anastomosis is most often used to treat chronic ulcerative colitis and inherited conditions, such as familial adenomatous polyposis (FAP), that carry a high risk of colon and rectal cancer.

In some instances, the procedure is done when medications used to treat ulcerative colitis fail to control the condition. It may also be done if precancerous changes or colon cancer are detected. Ileoanal anastomosis is also sometimes used to treat colon cancer and rectal cancer.