Histological Inflammation in the Endoscopically Uninflamed Mucosa is Associated With Worse Outcomes in Limited Ulcerative Colitis.

Background: The Montreal classification categorizes patients with ulcerative colitis (UC) based on their macroscopic disease extent. Independent of endoscopic extent, biopsies through all colonic segments should be retrieved during index colonoscopy. However, the prognostic value of histological inflammation at diagnosis in the inflamed and uninflamed regions of the colon has never been assessed.