Diversion colitis is inflammation that develops in a lower part of the large intestine after the passage of stool above this part has been surgically diverted.

Some people undergo an ileostomy (a surgically created connection between the lowest portion of the small intestine and an opening in the abdominal wall) or a colostomy (the surgical creation of an opening between the large intestine and the abdominal wall). Ileostomies and colostomies may be performed to treat diseases such as cancer, ulcerative colitis, and diverticulitis or to treat damage to the intestine due to an injury. In many people, especially when the doctor expects the need for the bypass of the large intestine to be temporary, either the entire large intestine or a portion of the large intestine is left in place below the point where the flow of stool is diverted.

In about one third of people who have all or a portion of their large intestine left in place after an ileostomy or colostomy, symptoms of diversion colitis, ranging from passage of mucus from the rectum to rectal bleeding and pain, may develop within 1 year after surgery. Most people do not require treatment because the symptoms remain mild. Surgery to reattach the two separated portions of the intestine and restore the normal flow of stool usually leads to resolution of the inflammation and symptoms.

Last full review/revision August 2006 by David B. Sachar, MD; Aaron E. Walfish, MD