The treatment outcomes were classified in terms of symptomatic, endoscopic, and histological improvement. The improvement in symptoms was defined as the resolution of the patient's presenting symptoms. The endoscopic improvement was divided into two subcategories: complete or partial endoscopic improvement. Disappearance of all abnormal endoscopic lesions seen on prior endoscopy in the follow-up endoscopy was the definition of complete endoscopic improvement, while the amelioration of the endoscopic findings in comparison with the previous study, e.g., smaller ulcer size or number and resolution of mucosal bleeding, but not completely resolute was characterized as partial improvement. Lastly, the histological improvement was defined by an absence of CMV staining on the follow-up tissue specimen.