Long-standing colonic inflammation is associated with a low prevalence of diverticula in inflammatory bowel disease patients

Background: Diverticulosis is associated with high intracolonic pressure and a weakened bowel wall. Chronic colitis is characterized by liquid stools suggestive of low intracolonic pressure and a thickened bowel wall. Therefore, the aim of this study was to assess the prevalence of diverticulosis in colitis patients. Methods: Colonoscopy results of patients with inflammatory bowel disease (IBD)-associated colitis older than 50 years were retrospectively evaluated and compared with those of patients who underwent screening colonoscopy. Only patients with biopsy-proven disease, disease duration of more than 5 years, and disease beyond the distal 20 cm were included. Results: In all, 1037 patients were diagnosed by colonoscopy as suffering from IBD-associated colitis between 1987-2005. After exclusion of patients who did not meet the inclusion criteria the study population consisted of 314 IBD patients and 1023 age-matched control patients. A significantly higher percent of diverticuli was detected in the control group compared with the IBD group (15% versus 3.5%, P < 0.001). No significant difference in the prevalence of diverticuli was detected between the three sub-types of IBD patients (2% in ulcerative colitis versus 4.7% in Crohn's colitis versus 7.6% in indeterminant colitis). Neither disease duration nor the specific colonic segment involved had a significant influence on the prevalence of diverticulosis. Conclusions: Long-standing colonic inflammation in IBD patients is associated with a lower prevalence of diverticuli.