1. Division of Gastroenterology, Department of Medicine, Faculty of Medicine, Chulalongkorn University; King Chulalongkorn Memorial Hospital, Thai Red Cross Society; Bangkok Thailand
2. Division of Gastroenterology; Sawanpracharak Hospital; Nakhon Sawan Thailand
3. Division of Gastroenterology; Surin Hospital; Surin Thailand
4. Division of Gastroenterology; HRH Princess Maha Chakri Sirindhorn Medical Center-MSMC Hospital; Bangkok Thailand
5. Division of Gastroenterology; Maharat Nakhon Ratchasima Hospital; Nakhon Ratchasima Thailand
6. Division of Gastroenterology; Maharaj Nakhon Si Thammarat Hospital; Nakhon Si Thammarat Thailand
7. Division of Gastroenterology; Chonburi Hospital; Chonburi Thailand
8. Division of Gastroenterology; Bangkok Hospital; Bangkok Thailand
9. Department of Surgery; Rajavithi Hospital; Bangkok Thailand
10. Division of Gastroenterology; Rajavithi Hospital; Bangkok Thailand
11. Division of Gastroenterology, Department of Medicine, Faculty of Medicine; Thammasat University Hospital; Pathum Thani Thailand
12. Division of Gastroenterology; Bangkok Metropolitan Administration General Hospital; Bangkok Thailand