1. Department of Medicine, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
2. University Medical Unit, Colombo North Teaching Hospital, Ragama, Sri Lanka
3. Department of Clinical Medicine, Faculty of Medicine, General Sir John Kotelawala Defence University, Rathmalana, Sri Lanka
4. Gastroenterology Unit, Department of Medicine, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
5. Department of Physiology, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka