Functional gastrointestinal disorders (FGID), including irritable bowel syndrome, functional dyspepsia and functional abdominal pain, are common in adolescents and are associated with substantially decreased quality of life. Cognitive behavior therapy for children and adolescents with FGID is one of few treatments that have shown effect, but treatment access is limited. In adults with irritable bowel syndrome, exposure-based internet-delivered CBT (ICBT) leads to reduced symptoms and increased quality of life, but studies in children are lacking. This open pilot aimed to evaluate feasibility and the potential efficacy of an exposure-based ICBT-program for adolescents with pain-predominant FGID. Twenty-nine adolescents (age 13–17), with FGID were included. The ICBT-program lasted for 8weeks with weekly online therapist support. The protocol for adolescents included exposure to abdominal symptoms, while the protocol for parents aimed at increasing parents' attention to adolescent healthy behaviors. Assessment points were baseline, post-treatment and 6-month follow-up. The primary outcome was the Gastrointestinal Symptoms Rating Scale-IBS (GSRS-IBS). Effect sizes were calculated using Cohen's d in an intent to treat analysis. GSRS-IBS improved significantly from baseline to post-treatment (mean difference 6.48; 95% CI [2.37–10.58]) and to follow-up (mean difference 7.82; 95% CI [3.43–12.21]), corresponding to moderate effect sizes (within-group Cohen's d =0.50; 95% CI [0.16–0.84] and d =0.63; 95% CI [0.24–1.02], respectively). Treatment adherence was high with 22 of 29 (76%) adolescents completing the entire treatment period. High adherence indicates acceptability of format and content, while symptomatic improvement suggests potential efficacy for this ICBT intervention in adolescents with FGID. 
Internet-delivered cognitive behavior therapy for adolescents with functional gastrointestinal disorders — An open trial