Rates of Diverticulosis in Patients with Inflammatory Bowel Disease

Abstract

Purpose: Diverticulosis of the colon is a common disease process of the Western world found in up to 50% of patients over age 60 presenting for screening colonoscopy. Studies have linked the condition to lack of dietary fiber intake in combination with the prolonged colonic transit time and increased intra-luminal pressure associated with low volume stools. Contrary to diverticulosis, chronic colitis seen in inflammatory bowel disease is characterized by liquid stools suggestive of low intra-colonic pressure and a thickened bowel wall. It is reasonable to hypothesize that these competing pathophysiologic events would produce an indirect correlation in disease prevalences. Methods: An electronic medical record database review was done selecting patients who carried a diagnosis of ulcerative colitis or Crohn's disease at our institution, who had undergone recent colonoscopy. Patients under age 50 or those who had undergone previous colonic surgery with resection of any portion of the distal transverse, descending, or sigmoid colon were excluded, due to the fact that the vast majority of patients with diverticular disease have evidence of disease in the distal colon. Endoscopically or pathologically proven active IBD was not necessary for inclusion. After initiation of the inclusion and exclusion criteria, there were 82 patients in the ulcerative colitis group and 63 in the Crohn's disease group. A control group of patients over age 50 who had recently undergone colonoscopy at our institution with no known diagnosis of either type of IBD, no post procedure diagnosis of IBD, no previous colonic surgery, and an indication not related to GI blood loss (melena, hematochezia, etc.) was selected. 101 patients were included in this group. Presence or absence of one or more diverticulum in any area of the colon was recorded. Results: Diverticulosis was less prevalent in patients with IBD. Of the 63 patients with known diagnosis of Crohn's disease, incidental diverticulosis was found in 12 (19%). Of the 82 patients with known diagnosis of ulcerative colitis, diverticulosis was found in 23 (28%). Of the control group of 101 patients, diverticulosis was found in 39 (38.6%). Of the 23 patients with ulcerative colitis found to have diverticulosis, further review showed that only 6 of these patients had evidence of active inflammation endoscopically. The majority (17) had endoscopically normal colons and presumed quiescent disease. Conclusion: Patients with inflammatory bowel disease have a lower prevalence of diverticulosis than the general population. This indirect correlation is probably less pronounced in those whose IBD is in remission.