1 Department of Paediatrics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, SAR, China.
2 Department of Medicine and Therapeutics, Division of Gastroenterology and Hepatology, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, SAR, China.
3 Institute of Digestive Disease, Chinese University of Hong Kong, Hong Kong, SAR, China.
4 Department of Paediatrics, Taipei Medical University Hospital, Taipei, Taiwan.
5 Taipei Medical University Research Center for Digestive Medicine, Taipei Medical University, Taipei, Taiwan.