1 Division of Gastroenterology, Department of Medicine, Rajavithi hospital, Ministry of Public Health, College of Medicine, Rangsit University, Bangkok, Thailand.
2 Institute of Gastrosciences and Liver Transplant, Apollo Multispecialty Hospitals, Kolkata, West Bengal, India.
3 Division of Gastroenterology and Hepatology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Faculty of Medicine, Chinese University of HongKong, Hong Kong, China.