Puo-Hsien Le,1,2 Chia-Jung Kuo,1–3 Ren-Chin Wu,3,4 Jun-Te Hsu,3,5 Ming-Yao Su,1–3 Chun-Jung Lin,1,3 Cheng-Tang Chiu1–3 1Department of Gastroenterology and Hepatology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan; 2Taiwan Association for the Study of Small Intestinal Diseases, Taoyuan, Taiwan; 3College of Medicine, Chang Gung University, Taoyuan, Taiwan; 4Department of Pathology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan; 5Department of General Surgery, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan Background: Cytomegalovirus (CMV) colitis typically presents in immunocompromised and inflammatory bowel disease (IBD) patients. Several studies have been conducted on the endoscopic characteristics of CMV colitis in IBD patients. Objectives: The endoscopic findings of CMV colitis in non-IBD patients and their relationship with inhospital mortality are unclear. We aimed to describe the endoscopic presentation in these patients and to determine the endoscopic predictors of inhospital mortality. Patients and methods: Patients with CMV colitis diagnosed using histology between April 2002 and December 2016 at the Linkou Chang Gung Memorial Hospital, Taiwan, were retrospectively enrolled. Patients diagnosed with IBD during follow-up were excluded. Patient data, including underlying diseases, endoscopic presentation, laboratory data, clinical course, complications, and clinical outcomes, were collected. The independent risk factors for inhospital mortality were analyzed with logistic regression. The difference of overall survival was compared using Kaplan–Meier survival curve and log rank test. All statistical calculations were performed using SPSS software, version 21. Results: Sixty-nine patients were enrolled, and 8 IBD patients were excluded. Within the 61 non-IBD patients, 31 were diagnosed by colonoscopy and others by sigmoidoscopy. Ulceration (77%) was the most common endoscopic finding, followed by a cobblestone appearance (19.7%), colitis with/without erosions (9.8%), pseudomembrane (9.8%), and tumor/polyp-like lesions (8.2%). Among the patients who underwent full-length colonoscopy, 35.3% presented with right-sided colitis, 23.5% with left-sided colitis, and 32.4% with pancolitis. Pancolitis was identified as a negative predictor of inhospital mortality (odds ratio, 6.8; 95% confidence interval, 1.233–37.497; p=0.028) and overall survival (log rank p=0.018). Conclusion: Colonoscopy is recommended for precise CMV colitis diagnosis and outcome prediction in non-IBD patients. Keywords: cytomegalovirus colitis, CMV, inflammatory bowel disease, endoscopy, colonoscopy, mortality