1. Department of Internal Medicine, Marshfield Clinic, Marshfield, WI, USA
2. Division of Digestive Diseases, Emory University School of Medicine, Atlanta, GA, USA
3. Division of Gastroenterology, King Chulalongkorn Memorial Hospital, Chulalongkorn University and Thai Red Cross, Bangkok, Thailand
4. Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, P. R. China
5. Department of Gastroenterology, Xijing Hospital, Xi’an, Shaanxi, P. R. China
6. Department of Gastroenterology, Nanjing Drum Tower Hospital, Nanjing, Jiangshu, P. R. China
7. Department of Gastroenterology, Renji Hospital, Shanghai Jiaotong University, Shanghai, P. R. China