1. Department of Gastroenterology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646099, China
2. Department of Gastroenterology, Lianshui County People’ Hospital, Huaian, Jiangsu 223400, China
3. Department of Gastroenterology, Lianshui People’ Hospital of Kangda College Affiliated to Nanjing Medical University, Huaian, Jiangsu 223400, China