1. Sheffield Teaching Hospitals NHS Foundation Trust, Academic Department of Gastroenterology, Sheffield, UK
2. Department of Psychology, University of Sheffield, Sheffield, UK
3. School of Pharmacy, University of Nottingham, Nottingham, UK
4. Sheffield Children’s Hospital NHS Foundation Trust, Department of Psychology, Sheffield, UK
5. School of Health and Related Research [ScHARR], Clinical Trials Research Unit, University of Sheffield, Sheffield, UK
6. Sheffield Children’s Hospital NHS Foundation Trust, Department of Gastroenterology, Sheffield, UK
7. Department of Oncology & Metabolism, University of Sheffield, Sheffield, UK