1. The Royal Wolverhampton NHS Trust, Wolverhampton, UK
2. University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
3. Neurogastroenterology Group, Blizard Institute of Cell & Molecular Science, Wingate Institute of Neurogastroenterology, Barts & the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
4. University of Keele, Keele, UK
5. Department of Gastroenterology, University Hospitals North Midlands, Stoke on Trent, UK