Routine colonoscopy following acute uncomplicated diverticulitis

Background: The evidence supporting current recommendations that the colon should be evaluated following an initial episode of acute diverticulitis is poor. The aim of this study was to clarify whether acute uncomplicated diverticulitis is a valid indication for subsequent colonoscopy/computed tomography (CT) colonography. Methods: This was a retrospective longitudinal study of patients with an initial presentation of acute uncomplicated diverticulitis on the basis of CT criteria, at a single institution between January 2004 and December 2008. Results: A radiological diagnosis of acute uncomplicated diverticulitis was made in 292 patients. Some 205 patients underwent subsequent colonic evaluation or had undergone colonoscopy/CT colonography within the preceding 2 years. Colorectal polyps were present in 50 patients (24.4 per cent). Twenty patients (9.8 per cent) had hyperplastic polyps and 19 (9.3 per cent) had adenomas. Eleven patients (5.4 per cent) had advanced colonic neoplasia, including one (0.5 per cent) with a colorectal cancer. One patient had inflammatory bowel disease (IBD). The patients with colorectal cancer and IBD had clinical indicators that independently warranted colonoscopy. None of the 87 patients who did not undergo colonic evaluation had a diagnosis of colorectal cancer registered with the New Zealand Cancer Registry. Conclusion: The yield of advanced colonic neoplasia in this cohort was equivalent to, or less than that detected on screening asymptomatic average-risk individuals. In the absence of other indications, subsequent evaluation of the colon may not be required to confirm the diagnosis of diverticulitis.