[1] Intestinal waste passes out of the ileostomy and is collected in an external ostomy system which is placed next to the opening.

Ileostomies are necessary where injury or a surgical response to disease has meant the large intestine cannot safely process waste, typically because the colon and rectum have been partially or wholly removed.

People with ileostomies typically use an open-ended (referred to as a "drainable") one- or two-piece pouch that is secured at the lower end with a leakproof clip, or velcro fastener.

[5][6] If the bag stays empty for more than four to six hours, individuals should contact their healthcare provider, as this may indicate intestinal blockage.

The stomal- or colorectal-nurse does this initially for a patient and advises them on the exact size required for the pouch's opening.

[8] Nevertheless, people who have an ileostomy as treatment for inflammatory bowel disease typically find they can enjoy a more "normal" diet than they could before surgery.

With lifestyle adjustments, those who have had this procedure for their Crohn's disease can resume normal bowel movements without artificial appliances.

[13] Since the late 1970s, an increasingly popular alternative to an ileostomy has been the Barnett continent intestinal reservoir (or BCIR).

The formation of this pouch (made possible through a procedure first pioneered by Nils Kock in 1969), involves the creation of an internal reservoir which is formed using the ileum and connecting it through the abdominal wall in a very similar fashion to a standard "Brooke" ileostomy.

[14] The BCIR procedure should not be confused with a J-pouch, which is also an ileal reservoir, but is connected directly to the anus—after removal of the colon and rectum—avoiding the need for subsequent use of external appliances.

The pouch works by storing the liquid waste, which is drained several times a day using a small silicone tube called a catheter.

Most patients cover the stoma site with a small pad or bandage to absorb the mucus that accumulates at the opening.

By the early 1970s, several major medical centers in the United States were performing Kock pouch ileostomies on patients with ulcerative colitis and familial polyposis.

This technique worked well, but after several years, the intestine reacted to the Marlex by forming fistulae (abnormal connections) into the valve.

[18] After a test series of over 300 patients, Barnett moved to St. Petersburg, Florida where he joined the staff of Palms of Pasadena Hospital, where he trained other surgeons to perform his continent intestinal reservoir procedure.

[17][Note 4] The end result of these developments has been a continent intestinal reservoir with minimal complications and satisfactory function.

[22][23][Note 5] Candidates for BCIR include: people who are dissatisfied with the results of an alternate procedure (whether a conventional Brooke ileostomy or another procedure); patients with a malfunctioning/failed Kock pouch or IPAA/J-pouch; and individuals with poor internal/external anal sphincter control who either elect not to have the J-pouch (IPAA) or are not a good candidate for IPAA.

[25] When Crohn's disease only affects the colon, it may, in select cases, be appropriate to perform a BCIR as an alternative to a conventional ileostomy.

A 1995 study by the American Society of Colon and Rectal Surgeons included 510 patients who received the BCIR procedure between January 1988 and December 1991.

"[24] In 1999, American Society of Colon and Rectal Surgeons published a unique study on 42 patients with a failed IPAA/J-pouch who converted to the Barnett modification of the Kock pouch (BCIR).