1. Department of Gastroenterology and Hepatology, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China
2. Department of Gastroenterology, Changhai Hospital, Second Military Medical University and Naval Medical University, Shanghai, China
3. General Hospital of Western Theatre Command, Chengdu, China
4. Department of Gastroenterology, Chengdu First People’s Hospital, Chengdu, China