[1] Sheffield Teaching Hosp NHS Fdn Trust, Acad Dept Gastroenterol, Sheffield, S Yorkshire, England
[2] Univ Sheffield, Dept Psychol, Sheffield, S Yorkshire, England
[3] Univ Nottingham, Sch Pharm, Nottingham, England
[4] Sheffield Childrens Hosp NHS Fdn Trust, Dept Psychol, Sheffield, S Yorkshire, England
[5] Univ Sheffield, Sch Hlth & Related Res ScHARR, Clin Trials Res Unit, Sheffield, S Yorkshire, England
[6] Sheffield Childrens Hosp NHS Fdn Trust, Dept Gastroenterol, Sheffield, S Yorkshire, England
[7] Univ Sheffield, Dept Oncol & Metab, Sheffield, S Yorkshire, England