1. Department of Medicine, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA
2. Medicine, Universitas Indonesia, Jakarta, Indonesia
3. Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA
4. School of Medical Sciences, Universiti Sains Malaysia, Kota Bharu, Malaysia
5. GI Function and Motility Unit, Hospital USM, Kota Bharu, Malaysia