OBSTRUCTIVE COLITIS - AN ANALYSIS OF 50 CASES AND A REVIEW OF THE LITERATURE

Obstructive colitis is an ulcero-inflammatory and necrotizing conditio n that occurs in the colon proximal to benign or malignant stenosing l esions. It is the result of ischemia due to impairment of blood supply secondary to elevation of the endoluminal pressure, distension of the colonic wall and other factors which impair adequate perfusion. The i ncidence among patients with colonic obstruction is reported at betwee n 1 and 7%. Of 50 patients with this condition in this series, 30 fema le and 20 male, 2/3rds were well over 70 yrs of age. Obstruction was m ost common in the rectosigmoid. in half the patients this was due to a denocarcinoma, 24 were due to benign obstruction and 15 were caused by diverticular disease. Type, extent and depth of ischemic lesions were highly variable and comprised early mucosal hemorrhage and edema, ulc erohemorrhagic lesions and transmural necrosis. There was always an ab rupt transition between affected and normal bowel. A segment of preser ved mucosa was usually present on the proximal side of the stenosis. I n 16 patients massive dilatation with stretching and thinning of the b owel wall, associated with a blow-out type of perforation or with tran smural necrosis, was observed and was considered to have resulted from a rapid rise of endoluminal pressure to high levels. The microscopic and macroscopic features are described in detail and histological fact ors discussed in relation to the pathological lesions encountered. Emp hasis is placed upon the range of appearances and similarities are sha red with other inflammatory colonic diseases, particularly idiopathic inflammatory bowel disease. The importance of recognition of this dise ase entity, not only by pathologists but by surgeons dealing with the disease at operation, is stressed.