1. Department of Gastroenterology, Dongyang People's Hospital of Zhejiang Province, Dongyang, Zhejiang 322100, P.R. China
2. Department of Gastroenterology, Weishan Branch of Dongyang People's Hospital of Zhejiang Province, Dongyang, Zhejiang 322100, P.R. China
3. Department of Gastroenterology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China