1. Department of Surgery, Queen Elizabeth Hospital, Lewisham and Greenwich NHS Trust
2. Department of Gastroenterology, Whipps Cross University Hospital, Barts Health NHS Trust, London
3. Department of Gastroenterology, The Hillingdon Hospitals NHS Foundation Trust, Middlesex, UK
4. Department of Gastroenterology, Northern Hospital, Epping
5. Department of Medicine, University of Melbourne, Parkville, Melbourne, Australia