Genetic Insights Reveal Chronic Pain and Mental Health as Modifiable Factors Increasing IBS Risk

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder impacting approximately 5% to 10% of the global population, characterized by symptoms such as abdominal pain, bloating, and irregular bowel habits. It significantly compromises quality of life and strains healthcare resources. Despite its widespread prevalence, the exact causes of IBS remain poorly understood, and preventive measures are limited.

In a groundbreaking study published in eGastroenterology, researchers led by Di Liu employed a comprehensive Mendelian randomization approach to explore causal relationships between modifiable factors and IBS. This method leverages genetic variants as instrumental variables, allowing scientists to discern genuine causal effects from mere associations.

The analysis integrated data from over 50 studies, involving 53,400 IBS cases and 433,201 controls, and validated findings in the FinnGen Biobank. The study examined more than 50 modifiable factors across seven domains, including lifestyle, social determinants, physical symptoms, and psychiatric conditions.

Findings revealed significant genetic correlations between IBS and various factors. Notably, multisite chronic pain exhibited the strongest causal link, supporting theories that pain sensitization and brain-gut axis dysfunction are central to IBS development. Other factors, such as smoking, alcohol consumption, low education level, childhood maltreatment, and psychiatric traits like neuroticism, depression, and anxiety, also showed associations.

Interestingly, dietary factors like tea and coffee intake, as well as physical activity, did not demonstrate consistent causal relationships, suggesting that previous observational links may be confounded.

The study also identified coexisting gastrointestinal conditions—such as gastroesophageal reflux disease and diverticular disease—and psychiatric disorders, including schizophrenia, depression, and bipolar disorder, as genetically linked to IBS.

Importantly, the analysis highlighted psychological and somatic factors as not just correlated but causally contributing to IBS. The robust link between multisite chronic pain and IBS persisted even after adjusting for psychiatric and gastrointestinal comorbidities, implicating mechanisms like central pain amplification and dysregulation of the brain-gut axis.

Psychological traits such as neuroticism and low positive affect were also identified as potential contributors, emphasizing the importance of mental health management in IBS prevention and treatment. Lifestyle factors, particularly smoking, appeared to influence IBS risk indirectly through psychiatric pathways.

These insights suggest that effective prevention strategies should incorporate the management of chronic pain syndromes and psychological health. Clinicians are encouraged to screen for and address comorbid conditions, adopting a multidisciplinary approach that targets shared risk factors.

This research advances our understanding of IBS by pinpointing modifiable, causal risk factors via genetic methods, shifting the focus from symptom management to risk reduction. Such strategies could improve patient outcomes and inform public health initiatives.

Source: https://medicalxpress.com/news/2025-05-chronic-pain-mental-linked-ibs.html