Diversion colitis is characterized by inflammation of the defunctionalized, bypassed colon following surgery [1,2]. Most patients with diversion colitis are asymptomatic; but, in a small proportion of patients, symptoms can significantly impact quality of life .
This topic will review the epidemiology, pathogenesis, clinical manifestations, diagnosis, and management of diversion colitis. The epidemiology, clinical manifestations, diagnosis, and management of ulcerative colitis and Crohn disease are discussed in detail, separately. (See "Definition, epidemiology, and risk factors in inflammatory bowel disease" and "Management of mild to moderate ulcerative colitis" and "Management of severe ulcerative colitis" and "Approach to adults with steroid-refractory and steroid-dependent ulcerative colitis" and "Clinical manifestations, diagnosis and prognosis of Crohn disease in adults" and "Overview of the medical management of mild to moderate Crohn disease in adults" and "Overview of the medical management of severe or refractory Crohn disease in adults".)
Diversion colitis or proctitis is a nonspecific inflammatory disorder that occurs in segments of the colon and rectum that are diverted from the fecal stream by surgery (eg, creation of a loop colostomy/ileostomy or an end-colostomy/ileostomy with closure of the distal colon segment [eg, Hartmann's procedure]).
The true incidence of diversion colitis is unknown. Several small observational studies have demonstrated histologic changes of diversion colitis in the distal colonic segment of 70 to 100 percent of patients with fecal diversion, and endoscopic evidence in 70 to 91 percent of patients [4-11]. (See 'Endoscopy and biopsy' below.)
ETIOLOGY AND PATHOGENESIS
Diversion colitis typically occurs in diverted segments of the colon following surgery for congenital, inflammatory, or neoplastic disorders. Patients usually have a loop colostomy (or ileostomy) or an end-colostomy (or ileostomy) with closure of the distal colon segment (eg, Hartmann's procedure). Diversion of the fecal stream results in a deficiency of short-chain fatty acids (SCFAs) and other luminal nutrients in colonocytes in the diverted segment of the colon. It is hypothesized that the lack of these compounds or interference with their metabolism by alterations in gut flora may have a role in the development of colitis [12,13].