1. Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai 200032, P.R. China
2. Department of Endoscopy, Zhongshan Hospital, Fudan University, Shanghai 200032, P.R. China
3. Department of Gastroenterology, Endoscopy Center, Evidence‑Based Medicine Center, Zhongshan Hospital, Fudan University, Shanghai 200032, P.R. China