The colon or the large intestine connects the small intestines to the rectum.

A colostomy is done when the lower large intestine, rectum, or anus is unable to function normally or needs rest from normal functions. Intestinal obstruction with associated inflammation, as in diverticulitis, is a common indication for colostomy.

A colostomy creates an opening on the abdomen (stoma) for the drainage of stool (feces) from the large intestine (colon). Colostomies are usually performed after the diseased colon has been removed.

Colostomies may be temporary or permanent. While the patient is deep asleep and pain-free (general anesthesia), an incision is made in the abdomen. The diseased colon is removed.

The proximal end of the healthy colon is then brought out to the skin of the abdominal wall, where it is sutured in place. An adhesive drainage bag (stoma appliance) is placed around the opening. The abdominal incision is then closed.

In more than 90% of the cases, the surgery is successful.

The patient may experience considerable pain after surgery as the anus tightens and relaxes. Medications to relieve pain may be used. To avoid straining, stool softeners will be used. Avoid any straining during bowel movement or urination. Soaking in a warm bath can bring additional comfort. Depending on the disease process being treated, colostomies can be "taken down" and the colon reconnected in a second operation within weeks to months after the first operation.