Jiarong Xie1, Linjie Lu2, Yishu Chen3, Lei Xu1, Chengfu Xu4. 1. Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Clinical Research Center for Digestive Diseases, Hangzhou, China; Department of Gastroenterology, Ningbo First Hospital, Ningbo, China. 2. Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Clinical Research Center for Digestive Diseases, Hangzhou, China; Department of Gastroenterology, Haining Branch of the First Affiliated Hospital, Zhejiang University School of Medicine, Haining, China. 3. Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Clinical Research Center for Digestive Diseases, Hangzhou, China. 4. Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Zhejiang Provincial Clinical Research Center for Digestive Diseases, Hangzhou, China; Department of Gastroenterology, Haining Branch of the First Affiliated Hospital, Zhejiang University School of Medicine, Haining, China. Electronic address: xiaofu@zju.edu.cn.