Meta-analysis of the role of colonoscopy after an episode of left-sided acute diverticulitis

Routine colonoscopy was traditionally recommended after acute diverticulitis to exclude coexistent malignancy. Improved CT imaging may make routine colonoscopy less required over time but most guidelines still recommend it. The aim of this review was to assess the role of colonoscopy in patients with CT-proven acute diverticulitis. PubMed and Embase were searched for studies reporting the prevalence of advanced colorectal neoplasia (ACN) or colorectal carcinoma in patients who underwent colonoscopy within 1 year after CT-proven left-sided acute diverticulitis. The prevalence was pooled using a random-effects model and, if possible, compared with that among asymptomatic controls. Seventeen studies with 3296 patients were included. The pooled prevalence of ACN was 6-9 (95 per cent c.i. 5-0 to 9-4) per cent and that of colorectal carcinoma was 2-1 (1-5 to 3.1) per cent. Only two studies reported a comparison with asymptomatic controls, showing comparable risks (risk ratio 1-80, 95 per cent c.i. 0-66 to 4-96). In subgroup analysis of patients with uncomplicated acute diverticulitis, the prevalence of colorectal carcinoma was only 0.5 (0-2 to 1.2) per cent. Routine colonoscopy may be omitted in patients with uncomplicated diverticulitis if CT imaging is otherwise clear. Patients with complicated disease or ongoing symptoms should undergo colonoscopy.