1 Department of Medicine, Division of Gastroenterology, Excellence Center for Gastrointestinal Endoscopy, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand; Department of Gastroenterology, Calmette Hospital, Phnom Penh, Cambodia.
2 Department of Medicine, Division of Gastroenterology, Excellence Center for Gastrointestinal Endoscopy, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand.
3 Department of Medicine, Division of Gastroenterology, Excellence Center for Gastrointestinal Endoscopy, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society; Excellence Center for Gastrointestinal Endoscopy, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, and Pancreas Research Unit, Division of Gastroenterology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.