METHODS SETTING AND PARTICIPANTS The study will be based at the Royal Manchester Children's Hospital, a regional Paediatric Gastroenterology referral centre. Children and adolescents with IBD from the North West of England and beyond are referred to this centre. Any patient who is aged between 8 and 16 years with a diagnosis of IBD will be eligible for entry into the trial. Eligible patients will be identified through the hospital's paediatric IBD database. There are currently about 250 eligible patients who attend the centre. Inclusion criteria are: patients aged between 8 and 16 years; diagnosis of IBD by established clinical, endoscopic, histological and radiological criteria; clinical remission defined as an abbreviated Paediatric Crohn's Disease Activity Index (aPCDAI) score of ≤10 (12) for patients with Crohn's disease or as a Paediatric Ulcerative Colitis Activity Index (PUCAI) score of <10 (13) for those with ulcerative colitis and indeterminate colitis; parental and child's consent to participate in the study. Exclusion criteria are active disease (aPCDAI>15 or PUCAI ≥15), and unwillingness to provide informed consent.