Ning Wei1,2, Zhiheng Zhong1,2, Ruihua Shi3,4. 1. Medical School of Southeast University, No. 87 Dingjiaqiao, Nanjing, 210009, China. 2. Department of Gastroenterology, Southeast University Affiliated Zhongda Hospital, No. 87 Dingjiaqiao, Nanjing, 210009, China. 3. Medical School of Southeast University, No. 87 Dingjiaqiao, Nanjing, 210009, China. ruihuashi@126.com. 4. Department of Gastroenterology, Southeast University Affiliated Zhongda Hospital, No. 87 Dingjiaqiao, Nanjing, 210009, China. ruihuashi@126.com.