The nature of inflammatory bowel disease in patients with coexistent colonic diverticulosis

Reports of segmental colitis with diverticula regard this entity as a local disease. Our goal was to reexamine the association of diverticula to colitis and question the relationship of colonic diverticulosis with generalized inflammatory bowel disease (IBD).

A retrospective database review of more than 1,600 patients matched 100 cases with IBD and colonic diverticulosis with a control group of 100 patients with IBD without diverticulosis. Patients were matched by gender, IBD diagnosis, and date of birth. Variables examined included disease distribution, strictures, fistulae, extraintestinal manifestations (EIMs), family history, and age at IBD diagnosis.

For all IBD diagnoses, more sigmoid inflammation occurred in cases with diverticular disease: 82% versus 65% for controls (P = 0.005), and in the rectum: 85% versus 69% for controls (P = 0.005). In the Crohn's disease with diverticulosis subset, sigmoid inflammation was more common: 70% versus 42% for controls (P = 0.007), and in the rectum: 70% versus 46% for controls (P = 0.02). Disease distribution was otherwise similar throughout the colon, ileum, and jejunum. The incidence of strictures (P = 0.99) and fistulae (P = 0.69) was similar. EIMs were more frequent in cases with diverticulosis: 28% versus 16% (P = 0.05). Family history of IBD was similar: 26% for cases and 16% for controls (P = 0.12). Age at IBD diagnosis was significantly greater in diverticulosis cases compared with controls: 51.5 years (+/-17.6) versus 42.8 years (+/- 17.5) (P < 0.001), respectively.

We observed an increased frequency of sigmoid and rectal inflammation, EIMs, and an older age of IBD onset in cases with diverticulosis. This suggests a role for diverticula in IBD beyond that of a mere coincidental finding.