1 West China School of Medicine, Sichuan University, Chengdu, Sichuan, China; Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
2 Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
3 Department of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, Sichuan, China. Electronic address: doctortonghuan@163.com.