1. Gastroenterology Department, Hangzhou Xiasha Hospital, Zhejiang 310016, China
2. Gastroenterology Department, Sir Run Run Shaw Hospital, Zhejiang University Medical College, Hangzhou, Zhejiang 310016, China
3. Division of Gastroenterology, Department of Internal Medicine, Carolinas Medical Center, Charlotte, NC 28203, USA
4. University of North Carolina at Chapel Hill, Charlotte Campus, USA