Functional gastrointestinal disorders in adults with epilepsy: associations with psychological symptoms, chronotype, and seizure burden

BACKGROUND: Epilepsy is frequently accompanied by psychiatric comorbidities, whereas functional gastrointestinal disorders are often overlooked. This study investigated the prevalence of functional gastrointestinal disorders in adult patients with epilepsy (PWE) and their associations with psychological symptoms, chronotype, and seizure characteristics. METHODS: In this cross-sectional case-control study, 100 adult PWE and 100 age- and sex-matched healthy controls (HC) were evaluated. Functional gastrointestinal disorders were assessed using Rome IV criteria and stool form with the Bristol Stool Form Scale. Depression and anxiety were measured with the Beck inventories, and chronotype with the Morningness-Eveningness Questionnaire. Clinical epilepsy variables and antiseizure medication profiles were recorded. RESULTS: Functional gastrointestinal disorders were significantly more prevalent in PWE than in HCs. Irritable bowel syndrome and functional constipation occurred more frequently in the PWE, and constipation-predominant stool patterns were markedly increased. Patients with epilepsy showed higher rates of moderate-to-severe depression and anxiety and a predominance of intermediate chronotype. Within the PWE, functional gastrointestinal disorders and constipation-predominant stool patterns were associated with higher psychological symptom burden, polytherapy, and ongoing seizures, but not with epilepsy subtype, electroencephalography, or magnetic resonance imaging findings. CONCLUSION: Adults with epilepsy exhibit a substantially increased burden of functional gastrointestinal disorders accompanied by elevated psychological symptoms and altered chronotype distribution. Gastrointestinal symptoms were largely unreported clinically, despite their association with greater disease complexity. Systematic screening for functional gastrointestinal disorders, mood symptoms, and chronotype may facilitate a more comprehensive and integrated approach to epilepsy care. These findings underscore the need for multidisciplinary assessment in practice.