1. Department of Small Bowel Intestinal, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
2. Department of Gastroenterology, The Third Affiliated Xiangya Hospital, Central South University, Chang Sha, PR China
3. Department of Gastroenterology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China
4. Department of Gastroenterology, The First Affiliated Hospital of Jishou University, Jishou, PR China.