Primary Headache Disorders in Pediatric Irritable Bowel Syndrome: Characterizing IBS-Associated Migraine Highlights

Background/Objectives: This study aimed to determine the prevalence of primary headache disorders in children and adolescents with irritable bowel syndrome (IBS), compare the clinical characteristics of IBS-associated and non-IBS headache populations, and identify factors associated with migraine and tension-type headache (TTH) in pediatric IBS. Methods: This retrospective observational study included 100 patients aged 6–18 years diagnosed with IBS according to the Rome IV criteria. All patients underwent systematic headache screening and neurological evaluation using the International Classification of Headache Disorders, 3rd edition. Age- and sex-frequency-matched control groups comprising 30 patients with migraine and 31 with TTH without gastrointestinal disease were included for comparison. Multivariable logistic regression analysis was performed to identify factors independently associated with migraine and TTH. Results: Primary headache disorders were identified in 61% of patients, including migraine in 30% and TTH in 31%. Migraine was significantly associated with female sex, increasing age, and a family history of headache. Compared with patients with migraine without IBS, those with IBS-associated migraine had a significantly higher prevalence of nausea (93.3% vs. 60.0%, p = 0.002), whereas headache frequency, duration, severity, photophobia, phonophobia, and vomiting were similar. No significant clinical differences were observed between IBS-associated and non-IBS TTH. Conclusions: Primary headache disorders, particularly migraine, are highly prevalent in pediatric IBS. The markedly increased frequency of nausea without differences in other headache characteristics represents a hypothesis-generating observation and may reflect an interaction between migraine-associated symptoms and the underlying gastrointestinal susceptibility associated with IBS, rather than evidence of a distinct migraine phenotype. Routine neurological assessment should be considered in children with IBS, particularly in female adolescents and those with a family history of headache.