Role of Hormonal Changes in The Pathophysiology of Irritable Bowel Syndrome

Irritable bowel syndrome is a functional gastrointestinal disorder of multiple factors precipitated by neuroendocrine and gut-brain axis dysregulations. In the pathophysiology of IBS, hormonal imbalances are presumed to play an essential role. There has not been any study up to the mark that would detail such changes in different subtypes of IBS. This study investigates the serum levels of cortisol, serotonin, cholecystokinin (CCK), and motilin from patients with IBS in comparison to healthy controls and their interrelations with BMI and different subtypes of IBS. A cross-sectional case-control study was carried out at Al-Husseini General Hospital, Karbala, Iraq, between November 2024 and April 2025. Seventy-eight patients with IBS were diagnosed based on the Rome IV criteria, together with 54 age- and sex-matched healthy controls. Participants who had any systemic, endocrine, or gastrointestinal comorbidity were excluded from the study. Serum hormone levels were estimated by ELISA. Subclassification of IBS patients was done as IBS-D, IBS-C, or IBS-M and further categorization according to BMI using WHO standards. The IBS group presented significantly higher serum levels of cortisol, serotonin, and CCK but lower motilin levels compared to controls. There were variations in hormone levels across the different subtypes of IBS. BMI was significantly correlated with cortisol, serotonin, and motilin levels.