Background

Although early adverse life events (EALs) are prevalent among patients with irritable bowel syndrome (IBS), the impact of fear or dissociation experienced during the trauma has not been evaluated. We investigated the prevalence of fear at the time of trauma and its association with IBS status among individuals with early-life trauma before the age of 18.

Methods

Among participants with ≥1 EAL, association of fear and dissociation with IBS status was determined with logistic regression, and improvement in prediction of IBS over ETI score alone was determined with the likelihood ratio test. Controlling for age, sex, and IBS status, we then examined the association of each EAL with reported fear.

Key results

Compared to healthy controls (HCs), IBS subjects reported a higher prevalence of fear (60.4% vs 36.2%, P < .0005) and dissociation (23.5% vs 13.0%, P < .0005) at the time of EAL. Fear, but not dissociation, improved prediction of IBS over the total number of EALs (odds ratio = 2.00, P < .0001).

Conclusions and inferences

This study highlights the importance of EAL-related factors such as fear in addition to the presence or absence of EALs in IBS pathophysiology.

Changes in brain-gut interactions have been implicated in the pathophysiology of chronic visceral pain in irritable bowel syndrome (IBS). Different mechanisms of sensitization of visceral afferent pathways may contribute to the chronic visceral pain reports and associated brain changes that characterize IBS. They include increased gut permeability and gut associated immune system activation, and an imbalance in descending pain inhibitory and facilitatory mechanisms. In order to study the involvement of these mechanisms, correlations between gut epithelial permeability and live bacterial passage, and structural and functional brain connectivity were measured in women with moderate-to-severe IBS and healthy women. The relationships between gut permeability and functional and anatomical connectivity were significantly altered in IBS compared with the healthy women. IBS participants with lower epithelial permeability reported increased IBS symptoms, which was associated with increased functional and structural connectivity in endogenous pain facilitation regions. The findings suggest that relationships between gut permeability and the brain are significantly altered in IBS and suggest the existence of IBS subtypes based on these interactions.