Irritable bowel syndrome and restless legs syndrome: a narrative review of epidemiological and pathophysiological overlap.

Background: Irritable bowel syndrome (IBS) and restless legs syndrome (RLS) are chronic, multifactorial disorders that have considerable impact on quality of life and common comorbidity with mood and sleep disorders. Objectives: The present narrative review consolidates existing literature to examine the epidemiological connection, shared pathophysiological mechanisms, and clinical implications of IBS-RLS comorbidity. Methods: A literature search was conducted using PubMed and Google Scholar (2015-2025). The inclusion criteria were adult population and peer-reviewed, full-text studies on co-occurrence or mechanism between RLS and IBS. There were 48 included articles after independent screening. Results: Observational studies report RLS prevalence in IBS patients of about 10-46%, compared with 3-14% in controls, indicating a likely bidirectional association. Both conditions share risk factors like female sex, psychiatric comorbidity, and autonomic dysfunction, and overlap in mechanisms including iron deficiency, neuroinflammation, neurotransmitter imbalance, gut-brain axis disruption, and microbial dysbiosis. This supports a neurogastroenterological link and suggests shared etiologic pathways, highlighting the value of routine reciprocal screening to improve diagnosis and quality of life. Conclusion: The co-occurrence of IBS and RLS underscores the necessity of increased clinical vigilance and combined care. Shared mechanisms increase the potential for specific therapy approaches, including dopaminergic drugs, iron supplementation, microbiota modifications, and mast cell stabilizers. Further longitudinal and mechanistic studies are needed to clarify causality and evaluate potential dual-purpose interventions, as current evidence is largely observational and limits causal inference.