The Natural History of Incidental Colonic Diverticulosis on Screening Colonoscopy

Background. The natural history of colonic diverticulosis is unclear. Methods. Patients with incidental diverticulosis identified in a previous prospective cross-sectional screening colonoscopy study were evaluated retrospectively for clinic or hospital visit(s) for diverticular disease (DD= acute diverticulitis or diverticular bleeding) using review of electronic health records and patient phone interview. Results. 826 patients were included in the screening colonoscopy study. Three were excluded for prior DD. In all, 224 patients (27.2%; mean age 62.3 ± 8.2) had incidental diverticulosis distributed in the left colon (67.4%), right colon (5.8%), or both (22.8%). Up-to-date information was available on 194 patients. Of those, 144 (74.2%) could be reached for detailed interview and constituted the study population. Over a mean follow-up of 7.0 ± 1.7 years, DD developed in 6 out of 144 patients (4.2%) (4 acute cases of diverticulitis, 1 probable case of diverticular bleeding, and 1 acute case of diverticulitis and diverticular bleeding). Two patients were hospitalized, and none required surgery. The time to event was 5.1 ± 1.6 years and the incidence rate was 5.9 per 1000 patient-years. On multivariate analysis, none of the variables collected at baseline colonoscopy including age, gender, obesity, exercise, fiber intake, alcohol use, constipation, or use of NSAIDs were associated with DD. Conclusion. The natural history of incidental diverticulosis on screening colonoscopy was highly favorable in this well-defined prospectively identified cohort. The common scenario of incidental diverticulosis at screening colonoscopy makes this information clinically relevant and valuable to physicians and patients alike.