1. Endoscopy Unit, Department of Internal Medicine, Prince Sattam bin Abdulaziz University Hospital, College of Medicine, Prince Sattam bin Abdulaziz University, Al Kharj, Saudi Arabia
2. Endoscopy Unit, Department of Internal Medicine, Limassol General Hospital, St George's Medical School, University of Nicosia, Nicosia, Republic of Cyprus
3. Department of Family Medicine, College of Medicine, Prince Sattam bin Abulaziz University, Al Kharj, Saudi Arabia
4. Endoscopy Unit, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
5. Endoscopy Unit, King Khaled Hospital and Prince Sultan Center for Health Care, Al Kharj, Saudi Arabia
6. Department of Family Medicine, AlKharj Military Hospital, Al Kharj, Saudi Arabia
7. Department of Internal Medicine, Security Forces Hospital, Riyadh, Saudi Arabia
8. Ibn Sina National College for Medical Studies, Jeddah, Saudi Arabia
9. Almaarefa Medical College, Riyadh, Saudi Arabia