Tao Yu1, Yan-Qiu Yue2, Jian Chen1, Hong-Bao Ren1, Rui Ji1, Bao-Quan Cheng3. 1. Department of Gastroenterology, Qilu Hospital, School of Medicine, Shandong University, Jinan 250012, China. 2. Department of Gastroenterology, Binzhou People's Hospital, Binzhou 256610, China. 3. Department of Gastroenterology, Qilu Hospital, School of Medicine, Shandong University, Jinan 250012, China. Electronic address: drcbq@163.com.