1. Department of Gastroenterology, Minda Hospital of Hubei Minzu University, Enshi, Hubei 445000, P.R. China
2. Department of Infectious Diseases, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
3. Department of Gastroenterology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China