INTRODUCTION

Ulcerative colitis is an inflammatory bowel disease of uncertain etiology that is characterized by recurring episodes of inflammation primarily involving the mucosal layer and occasionally the submucosa of the colon. (See "Clinical manifestations, diagnosis, and prognosis of ulcerative colitis in adults".)

Terminology — Different terms are used to describe the extent of involvement [1]:

• Ulcerative proctitis refers to disease limited to the rectum.
• Ulcerative proctosigmoiditis refers to disease limited to the rectum and sigmoid colon, and not involving the descending colon. Although the term proctosigmoiditis is no longer used commonly, we will use it in this topic review because disease involving the rectum and sigmoid responds much better to topical rectal therapy than does left-sided colitis.
• Left-sided or distal ulcerative colitis is defined as disease that extends beyond the rectum and as far proximally as the splenic flexure.
• Pancolitis is often used when the inflammatory process extends beyond the splenic flexure, even though many of these patients will not have inflammatory bowel disease to the cecum. Some use the term extensive colitis rather than pancolitis for disease that extends beyond the splenic flexure but not as far as the cecum.

The medical management of ulcerative proctitis and left-sided ulcerative colitis will be reviewed here. Although the principles of treatment are the same as for more extensive ulcerative colitis, the limited extent of the disease permits more intensive use of rectally administered therapy that, in many patients, may be sufficient to induce and maintain remission [2]. The following discussion is consistent with published guidelines [1,3-7].

Overviews of the diagnosis and medical management of ulcerative colitis including more extensive colitis are discussed separately. (See "Clinical manifestations, diagnosis, and prognosis of ulcerative colitis in adults" and "Medical management of ulcerative colitis".)