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

Background 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. Methods 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. Results 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. Conclusion 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. This systematic review demonstrates that the prevalence of colorectal cancer in all patients with diverticulitis is slightly higher than in controls, whereas patients with uncomplicated diverticulitis have a colorectal cancer prevalence comparable to that of asymptomatic controls from the literature. Therefore, routine colonoscopy should be omitted in those with uncomplicated diverticulitis and these patients may be referred back to the colorectal cancer screening programme. However, routine colonoscopy should remain the protocol for differential diagnosis after non‐surgical treatment of complicated diverticulitis. Not needed routinely