Segmental colitis associated with diverticulosis syndrome.

An inflammatory process that involves the sigmoid colonic segment associated with diverticular disease (SCAD) appears to be a distinct clinical and pathological disorder. It has been described in older adults, often presenting with rectal bleeding. Most of the patients seem to respond to treatment only with a 5-aminosalicylate, but some spontaneously resolve with no treatment. Endoscopic evaluation usually shows a non-specific inflammatory process localized in the sigmoid colon alone that may resolve completely with histologically normal colonic mucosa. Repeated symptomatic events with discrete episodes of segmental colitis may occur, but most patients have an entirely benign clinical course. Definition of the underlying molecular events that occur with SCAD may be critically important in understanding the critical elements present in a colonic inflammatory process that can completely resolve without pharmacological or biological treatment.