The gut-brain axis represents one of the most intricate and rapidly evolving frontiers in modern medicine, bridging gastrointestinal physiology with neuroscience, immunology, and behavioral science. Irritable bowel syndrome, conceptualized within the paradigm of disorders of gut-brain interaction, exemplifies the profound clinical consequences when this bidirectional communication network becomes dysregulated. This narrative review examines the multidimensional mechanisms through which psychological stress disrupts gut-brain homeostasis, focusing on the hypothalamic-pituitary-adrenal axis, altered neurotransmitter signaling, visceral hypersensitivity, and gut microbiome perturbations. We explore how chronic psychological stress precipitates and perpetuates IBS symptomatology through immune activation, increased intestinal permeability, and aberrant processing of visceral afferent signals. Furthermore, this review synthesizes current evidence supporting integrated therapeutic approaches that target both psychological and gastrointestinal dimensions, including brain-gut psychotherapies, dietary modifications, pharmacological agents, and microbiome-targeted interventions. Understanding these interconnected pathways is essential for developing personalized treatment strategies that acknowledge the inseparable unity of mind and gut in health and disease.

gut-brain axis, irritable bowel syndrome, psychological stress, HPA axis, visceral hypersensitivity, gut microbiome, neurotransmitters, brain-gut psychotherapy, disorders of gut-brain interaction

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