1. Department of Internal Medicine
2. Department of Internal Medicine, Section of Digestive Diseases
3. Department of Medicine, Section of Digestive Diseases, Yale School of Medicine, New Haven, CT
4. Department of Internal Medicine, Division of Gastroenterology and Hepatology, King Faisal Specialist Hospital and Research Center
5. College of Medicine, Alfaisal University
6. Department of Biostatistics, Epidemiology and Scientific Computing, King Faisal Specialist Hospital, Riyadh, Saudi Arabia
7. Division of Gastroenterology, Warren Alpert Medical School, Brown University, Providence, RI