Risk of colorectal advanced neoplasia in patients with acute diverticulitis with and without previous colonoscopy

Abstract

Background and Aim: Guidelines recommend a colonoscopy after an episode of complicated diverticulitis and after a first episode of uncomplicated diverticulitis. The influence of a previous colonoscopy on postdiverticulitis colonoscopic findings has not been studied. The aim of this work was to examine the incidence of adenoma detection rate (ADR), advanced adenoma (AA) and colorectal cancer (CRC) in patients with diverticulitis with and without previous colonoscopy. Method: This was a retrospective case–control study of subjects with acute diverticulitis. Subsequent and previous colonoscopies were abstracted for ADR, AA and CRC diagnoses. The incidence of neoplasia was compared between patients with and without previous colonoscopy and also with that of a screening population. Results: Compared with a healthy control group (n = 975), diverticulitis patients without prior colonoscopy (n = 325) had a significantly higher ADR (26.8% vs. 20.5%, p = 0.019) and invasive CRC rate (0.9% vs. 0%, p = 0.016). Risk factors for advanced neoplasia included age ≥ 70 years and complicated diverticulitis. Among subjects with diverticulitis and previous colonoscopy (n = 124), only one patient developed AA and there were no cancer cases. Conclusions: A previous normal colonoscopy within 5 years before diverticulitis probably overshadows other risk factors for findings of advanced neoplasia and should be considered in the decision to repeat a colonoscopy.