1. Department of Medicine, Section of Gastroenterology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
2. Department of Medicine, King Khalid University, Abha, Saudi Arabia
3. Division of Gastroenterology, Department of Medicine, College of Medicine, King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia
4. Center for Esophageal Diseases and Swallowing, University of North Carolina School of Medicine, USA
5. Division of Pediatric Gastroenterology, Children’s Specialized Hospital, King Fahad Medical City, Riyadh, Saudi Arabia