1. *Senior Registrar, Gastroenterology Division, Department of Medicine, Riyadh Armed Forces Hospital, Riyadh 11159, Saudi Arabia
2. † Consultant Physician, Department of Medicine, Riyadh Armed Forces Hospital, Riyadh 11159, Saudi Arabia
3. § Formerly Consultant Microbiologist, Department of Pathology, Riyadh Armed Forces Hospital, Riyadh 11159, Saudi Arabia
4. ** Consultant Physician, Head, Gastroenterology Division, Department of Medicine, Riyadh Armed Forces Hospital, Riyadh 11159, Saudi Arabia