Colostomy

A colostomy is a type of stoma made from the large bowel (colon). In the operation, a surgeon brings part of the colon through an opening in the abdominal wall and turns it back on itself so the moist inner lining sits at the surface, giving stool a new way to leave the body into a pouch instead of passing through the rectum (Cleveland Clinic; NHS: Colostomy).

The name tells you what the stoma is connected to. A colostomy is made from the colon, which sets it apart from an ileostomy (made from the small intestine) and a urostomy (which drains urine).

What the output is like

Because the colon's main job is to absorb water from waste, stool that reaches a colostomy has usually had most of its water removed, so the output tends to be more formed than an ileostomy's. The exact consistency depends on which part of the colon the stoma is made from (Cleveland Clinic).

Where it sits on the abdomen

The most common type is a sigmoid colostomy, made from the lower S-shaped part of the colon and usually placed on the lower-left side of the belly. Because waste passes through nearly all of the colon first, the stool is firmer. A transverse colostomy sits higher, across the upper abdomen; since stool has travelled only about halfway through the colon, its output is softer (Cleveland Clinic).

Why it is done, and for how long

A colostomy can be temporary or permanent. Temporary reasons often include diverticulitis, inflammatory bowel disease, a bowel obstruction, or an injury, where the bowel is given time to heal before a later operation can reverse the stoma. Permanent reasons include advanced colorectal cancer, lasting faecal incontinence, or removal of the rectum and anus (Cleveland Clinic). Whether a colostomy can be reversed depends on why it was made and on your own recovery, which is a question for your surgical and stoma care team.