1. Hepatogastroetnerology, Kasr Al-Ainy Hospitals, Faculty of Medicine, Cairo University., Cairo, Egypt
2. Department of Medicine, Stockport Hospital NHS Foundation Trust, Hazel Grove, United Kingdom
3. Public Health Authority, Saudi Center for Disease Prevention and Control, Jazan, Saudi Arabia
4. Internal Medicine Department, Division of Gastroenterology, Kasr Al-Aini School of Medicine, Cairo, Egypt