Differentiating Colorectal Carcinoma From Diverticulitis With Computerised Tomography: Does Every Patient Need Follow-Up Colonoscopy After an Episode of Acute Diverticulitis?

Purpose To correlate computerised tomography (CT) and endoscopic follow-up (FU) in differentiating presentations of acute diverticulitis (AD) and colorectal carcinoma (CRC). Methods Patient's discharge summaries between April 2018 and September 2019, stating AD under-diagnosis were retrieved. Admission details, CT reports, endoscopic findings and histopathology results were retrospectively collected from prospectively maintained data. Results In our study period of 17 months, we identified 150 patients with an admission diagnosis of AD. In total, 134 patients had a CT confirmed diagnosis of AD; 61% had uncomplicated acute diverticulitis (UAD) and 39% complicated acute diverticulitis (CAD). The mean age of the patients was 64 years, and 59% were female. Of the 134, 15 patients were excluded, and 119 with AD were discharged with a plan to have FU endoscopy. Overall, 75% of the patients managed to undergo complete endoscopic investigation, 4% had incomplete endoscopy, and 21% failed to attend endoscopy. Follow-up (FU) endoscopic investigation found polyps in 20 patients; seven were reported as tubular adenomas with low-grade dysplasia and 10 as non-concerning hyperplastic or sessile polyps. One was inflammatory, and two were malignant. CT scans for two patients with malignant polyps were reported as CAD with suspicion of sigmoid cancer in one and right-sided perforated diverticulitis in the other. Both patients were female aged over 60 years. Conclusions This study demonstrates that a selective approach is more appropriate for endoscopic FU after an episode of AD. Risk stratification is required to allocate FU endoscopic investigation for patients at high risk for CRC.