1. Nanjing Drum Tower Hospital Clinical College, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210008, P.R. China
2. Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University, Nanjing, Jiangsu 210008, P.R. China
3. Department of Gastroenterology, Jinling Hospital, Nanjing, Jiangsu 210002, P.R. China