1 foundation trainee, Royal Bolton Hospital, Bolton, UK.
2 professor of gastroenterology, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK, and Department of Gastroenterology, Salford Royal Foundation Trust, Salford, UK.
3 clinical scientist, Department of Nuclear Medicine, Salford Royal Foundation Trust, Salford, UK.
4 consultant physicist, Department of Nuclear Medicine, Salford Royal Foundation Trust, Salford, UK.
5 gastroenterologist, Department of Gastroenterology, Salford Royal Foundation Trust, Salford, UK.