Colonoscopy After Acute Diverticulitis: Low Yield in Uncomplicated Disease, Higher Risk in Complicated Cases

Background: The optimal role of routine colonoscopy following an episode of acute diverticulitis remains a subject of ongoing debate, with contemporary guidelines increasingly advocating for a selective, risk-based approach. This study aimed to evaluate the diagnostic yield of colonoscopy after diverticulitis and to assess the influence of disease complexity on the detection of colorectal neoplasia. Methods: A retrospective cohort study was conducted on 268 patients with CT-confirmed acute diverticulitis. Colonoscopy was performed in 168 patients (62.7%). Patients were categorized into uncomplicated (n=179, 66.8%) or complicated (n=89, 33.2%) diverticulitis based on established radiological and clinical criteria. Colonoscopic findings were classified as normal mucosa, diverticulosis, benign polyps, strictures, or colorectal cancer. The association between disease complexity and colonoscopic findings was assessed using chi-square testing. Results: Among the 168 patients who underwent colonoscopy, the predominant finding was diverticulosis (n=137, 81.5%), followed by normal mucosa (n=16, 9.5%), benign polyps (n=10, 6.0%), strictures (n=4, 2.4%), and colorectal cancer (n=1, 0.6%). Of these, 115 patients (68.5%) had uncomplicated diverticulitis and 53 (31.5%) had complicated diverticulitis. All malignant pathology (n=1, 0.6%) occurred exclusively in the complicated group, yielding a cancer detection rate of 1.9% (1/53) in complicated diverticulitis versus 0% (0/115) in uncomplicated diverticulitis. Benign polyps were similarly distributed between groups, while strictures were more frequent in complicated disease. Normal colonoscopy findings were more common after uncomplicated episodes. Conclusion: Colonoscopy performed after uncomplicated diverticulitis demonstrated a very low diagnostic yield for colorectal cancer. Conversely, malignancy was exclusively identified in patients with complicated disease. These findings support a selective strategy, prioritizing colonoscopy for patients with complicated diverticulitis or those with additional risk factors, rather than a universal post-diverticulitis endoscopic evaluation.