1. Department of Gastroenterology, Central Hospital Affiliated to Shandong First Medical University, 105 Jiefang Road, Lixia District, Jinan, Shandong, China
2. Department of Internal Medicine, Shandong Provincial Police Officer General Hospital, 134 Yingxiong Mountain Road, Shizhong District, Jinan, Shandong, China
3. Department of Gastroenterology, Central Hospital Affiliated to Shandong First Medical University (Shandong Academy of Medical Sciences), 105 Jiefang Road, Lixia District, Jinan, Shandong, China