1. Department of Medicine, College of Medicine, Gastroenterology & Hepatology Unit, University of Ibadan, Ibadan, Nigeria
2. Department of Medicine, Gastroenterology & Hepatology Unit, University College Hospital, Ibadan, Nigeria
3. Department of Surgery, College of Medicine, Division of Gastrointestinal Surgery, University of Ibadan, Ibadan, Nigeria
4. Department of Anaesthesia, College of Medicine, University of Ibadan, Ibadan, Nigeria