Natural history and long-term clinical behavior of segmental colitis associated with diverticulosis (SCAD syndrome).

Localized inflammation of the sigmoid colon or segmental colitis associated with diverticulosis (SCAD syndrome) is an increasingly recognized, apparently uncommon, clinical and pathological disorder usually described in older adults. In the present study, 24 symptomatic patients, including 14 males, (58.3%) and 10 females (41.7%) were evaluated over a 20-year period with follow-up intervals ranging from 2 to 16 years. In most, initial clinical symptoms appeared after age 40 years and included rectal bleeding, diarrhea, and abdominal pain. Most (21 of 24, over 80%) initially responded with long-term resolution of their disease after treatment only with a 5-aminosalicylate. In addition, however, spontaneous remissions without any form of drug therapy were documented. In some, persistent, chronically active disease or true episodic recurrences were seen, leading to use of corticosteroids and/or resective surgery. Evidence here also suggested that colonic neoplasia, including adenoma development and cancer, were not related to the presence of this uniquely localized mucosal inflammatory process defined within the sigmoid colon. This study documents the natural history and long-term clinical behavior of this unusual segmental inflammatory process, associated with diverticulosis, and provides additional strong evidence that the SCAD syndrome is very distinct and can be readily separated from other forms of chronic inflammatory bowel disease.