1. Gastroenterology and Hepatology Department, University of Damascus, Damascus, Syria
2. Division of Internal Medicine, Creighton University Medical Center, Omaha, Nebraska, United States
3. Division of Internal Medicine, Sheikh Khalifa Medical City, Abu Dhabi, UAE
4. Department of Internal Medicine, Division of Digestive Diseases, Rush University Medical Center, Chicago, Illinois, United States
5. Gastroenterology and Hepatology Department, Oak Hill Hospital, Brooksville, Florida, United States