Introduction. Evidence from studies in adults documents that fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) may be triggers of symptoms in individuals with functional abdominal pain disorders. However, in children with FAPDs, there is a need for high-quality evidence regarding the dietary management. We aim to assess the effects of a low-FODMAP diet compared with a regular diet for the management of children with FAPDs.~Methods. In this trial, seventy-four children aged 8 to 18 years with a Functional Abdominal Pain Disorder (Irritable Bowel Syndrome or Functional Abdominal Pain-Not Otherwise Specified), diagnosed according to the Rome IV criteria, will be randomly allocated to receive either a low-FODMAP diet or a regular diet for 4 weeks.A primary outcome will be the percentage of the responders, defined as the participants who have at least 30% improvement in abdominal pain intensity on a Visual Analogue Scale (VAS) during the last week of the trial compared with baseline, that is at least equal to the Reliable Change Index (≥ 25 mm change on VAS).
This single-center, randomized, controlled, quadruple-blinded, superiority trial is performed to test the hypothesis that children with IBS and FAP-NOS who receive a low-FODMAP diet will have a lower mean abdominal pain intensity score compared with those who receive a regular diet after 4 weeks of intervention.