Peppermint Oil and Sweets in Pediatric Irritable Bowel Syndrome and Functional Abdominal Pain: A Randomized Trial

Background & Aims Effective pharmacologic treatment for pediatric irritable bowel syndrome (IBS) and functional abdominal pain—not otherwise specified (FAP-NOS) is lacking. This study evaluated the efficacy and safety of peppermint oil, an antispasmodic agent, and peppermint sweets in children with IBS or FAP-NOS. Methods This randomized controlled trial was conducted across 13 Dutch hospitals. Participants (aged 8–18 years) with IBS or FAP-NOS were randomized (1:1:1) to double-blind peppermint oil capsules (containing 182 mg of peppermint oil), open-label peppermint sweets (9.2 mg peppermint oil), or double-blind placebo (2.0 mg peppermint oil to enhance blinding) twice daily (8–11 years) or 3 times daily (12–18 years), with dose escalation if needed. The intervention lasted 8 weeks with a 4-week follow-up. The primary endpoint was treatment success, defined as a =30% reduction of abdominal pain intensity after 8 weeks. The key secondary endpoint was adequate relief of symptoms. Results In 228 children (8–11 years: n = 92; 12–18 years: n = 135; 75–78 per group), treatment success was comparable between patients receiving peppermint oil (n = 30; 44.0%) and placebo (n = 28; 37.3%) (odds ratio [OR], 1.33; 97.5% confidence interval [CI], 0.58–3.09; P = .44), and between placebo and peppermint sweets (n = 30; 38.7%) (OR, 1.05; 97.5% CI, 0.45–2.44; P = .91). Adequate relief was comparable between treatment groups: peppermint oil (n = 40; 53.3%) vs placebo (n = 37; 49.3%) (OR, 1.15; 97.5% CI, 0.54–2.47; P = .68), and placebo vs peppermint sweets (n = 35; 44.9%) (OR, 0.81; 97.5% CI, 0.39–1.71; P = .53). Adverse events were mild and infrequent. Conclusions Neither peppermint oil nor peppermint sweets were superior to placebo in treating pediatric IBS and FAP-NOS. These findings suggest prioritizing proven gut-brain axis-targeted interventions for this population. ClinicalTrials.gov , Number: NCT05799053 .