1. Department of Gastroenterology, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110000, P.R. China
2. Department of Gastroenterology, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110000, P.R. China
3. Department of Geriatrics, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110000, P.R. China