Routine Colonoscopy after Acute Uncomplicated Diverticulitis - Challenging a Putative Indication

Most international guidelines recommend performing a routine colonoscopy after the conservative management of acute diverticulitis, mainly to rule out a colorectal malignancy; however, data to support these recommendations are scarce and conflicting. This study is aimed at determining the rate of advanced colonic neoplasia (ACN) found by colonoscopy, and hence the need for routine colonoscopy after CT-diagnosed acute diverticulitis.

We retrospectively analyzed all patients hospitalized for acute diverticulitis between July 2008 and June 2013. Patients who underwent colonoscopy more than 1 year after the acute episode were excluded. Advanced adenoma (AA) was defined as an adenoma with: (i) ≥10 mm, (ii) ≥25% villous features, or (iii) high-grade dysplasia. ACN included cases of colorectal cancer (CRC) and AA.

Of the 364 selected patients, 252 (69%) underwent colonoscopy (51% women, median age 55 ± 11 years). Adenomatous polyps were evident in 14.7% patients; 5.1% had AA and 3.2% had CRC. Patients with complicated diverticulitis had a higher number of ACN compared to those with uncomplicated diverticulitis (20.9 vs. 5.7%, p = 0.003). On multivariate analysis, age ≥50 years (OR 8.12, 95% CI 2.463-45.112; p = 0.017) and abscess on CT (OR 3.15, 95% CI 1.586-11.586; p = 0.036) were identified as significant risk factors for ACN.

Patients with diverticulitis complicated with abscess have a higher risk of ACN on follow-up colonoscopy. The prevalence of ACN in patients with uncomplicated diverticulitis is quite similar to the average-risk population, and therefore an episode of CT-diagnosed uncomplicated diverticulitis, per se, does not seem to be a recommendation for colonoscopy.