During the ileal pouch-anal anastomosis (IPAA) procedure, a pouch is created from the end of a patient’s small intestine and attached to the anus. This restores continuity and control of stool passage for patients who have had their large intestines removed. It is referred to as an ileal pouch because it is made out of a portion of the small intestine, or ileum. An anastomosis is a surgically-created connection between tubular structures in the body, such as intestines.
Why remove the large intestine?
Certain medical conditions, such as ulcerative colitis (UC), familial adenomatous polyposis (FAP), and hereditary non-polyposis colorectal cancer (HNPCC), may require removal of the large intestine (colon and rectum). Removal of the large intestine is called a colectomy. Though the large intestine is not necessary for survival, without a rectum to serve as a storage area for stool, bowel movements cannot be controlled. Patients who have had a colectomy have several options for stool management. Two of the options are discussed below.
Patients with an ileostomy have a surgically-created opening in their abdomen referred to as a stoma. The small intestine (ileum) connects to the opening, and stool passes out of this opening into a bag worn outside the body. The bag is periodically emptied or replaced.
Ileal Pouch-Anal Anastomosis (IPAA)
The ileal pouch-anal anastomosis (IPAA) is a procedure developed in the 1980s that eliminates the need for a permanent stoma. During IPAA surgery, the patient's large bowel is removed, and the small bowel is connected to the anus. The last few inches of the small bowel are used to create an internal pouch which serves the function of a rectum. By preserving the anus and creating a new storage place for stool, patients are able to maintain control over their bowel habits and can continue to eliminate waste through the anus.
IPAA is commonly performed in two steps and requires a temporary ileostomy (stoma) for the time between the two separate surgeries.
During the first operation, both the colon and rectum are removed, and a pouch is created by folding back the final segment of the small intestine. After the pouch is created, the patient will have an ileostomy for approximately two months, which allows time for the bowel and newly-formed pouch to heal.
During the second operation the ileostomy is reversed (closed). The pouch will now act as the storage area for stool. Conscious control of the muscles in the anus is retained, allowing the patient to eliminate stool normally. After the IPAA procedure is complete, patient will usually have 4 to 6 bowel movements per day. While this frequency is still more than individuals with a healthy large intestine and rectum, it is manageable and generally does not interfere with daily life.
Our experience with the IPAA procedure
Over the last 30 years, IPAA has become the surgical treatment of choice for patients with ulcerative colitis and familial adenomatous polyposis. During this time, Dr. James Becker has performed over 850 ileal pouch-anal anastomosis procedures. Most of the IPAA surgeries Dr. Becker performs are done in two stages, requiring the use of a temporary diverting loop ileostomy. This allows time for the anastomosis to heal before stool is passed through it.