Catharine M. Walsh, MD, MEd, PhD, FRCPC is an Associate Professor of Paediatrics at The Hospital for Sick Children, University of Toronto, Toronto, Canada.

Ahmir Ahmad, MBBS, BSc, MRCP, PhD is a Consultant Gastroenterologist at St. Mark's Hospital, London, UK.

Brian P. Saunders, MD, FRCP, FRCS is a Consultant Gastroenterologist at St. Mark's Hospital and Professor of Endoscopy at Imperial College, London, UK.

Jonathan Cohen, MD, FASGE, FACG is a Clinical Professor of Medicine at the NYU Grossman School of Medicine, New York, USA.

Peter B. Cotton, MD, FRCP, FRCS is a Professor of Medicine at the Medical University of South Carolina, Charleston, USA.

Christopher B. Williams, BM, FRCP, FRCS was a Consultant Physician in Gastrointestinal Endoscopy at St. Mark's Hospital, London, UK.