Routine Endoscopy After Acute Sigmoid Diverticulitis: Would a Sigmoidoscopy be Sufficient?

Background: Current guidelines suggest that patients should undergo colonoscopy after CT confirmed acute diverticulitis to outrule colorectal cancer (CRC). The aim of this study was to determine if flexible sigmoidoscopy (FS) could be a viable alternative to full colonoscopy following acute sigmoid diverticulitis. Methods: A retrospective study of 271 patients was performed who were diagnosed with acute sigmoid diverticulitis by CT and subsequently underwent full colonoscopy. Medical records, CT reports, endoscopy reports, and histopathological reports were reviewed. Results: Sigmoid diverticulosis was confirmed on colonoscopy in all patients. No colorectal malignancies were detected. Adenomatous polyps were found in 16 (5.9%) patients, of which three had polyps detected beyond the sigmoid colon. The overall proportion of abnormalities found beyond the sigmoid colon was 1.1% (n=3). Conclusion: The detection of CRC cancer in patients undergoing full colonoscopy following an episode of acute sigmoid diverticulitis is rare. Despite this, current guidelines still advocate for endoscopy due to the potentially serious consequences of a missed malignancy. However, given that the area of concern in these cases is the sigmoid colon, FS may be a feasible means of outruling malignancy in the absence of red flag features that would necessitate a full colonoscopy. Our results support this approach, with no CRC detected and a polyp detection rate equivalent to that of the general population. This offers numerous advantages to a full colonoscopy for the patient and health service by being a quicker, cheaper, safer procedure without the need for full bowel preparation or IV sedation.