Mediating effect of coping dispositions on the association between trauma and gastrointestinal symptoms

Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are two gastrointestinal (GI) conditions known to be exacerbated by traumatic life experiences. One way in which these experiences might influence individuals' susceptibility to GI pathology, is by reducing their ability to deal with adversities effectively and predisposing them to passive coping styles that leave them vulnerable to the somatic effects of trauma. To validate this hypothesis, the present cross-sectional study assessed the mediating effect of coping dispositions on the association between trauma and GI disease activity in an adult sample of 189 bowel patients (94 IBD, 95 IBS) and 92 controls. Results confirmed that GI patients exhibit significantly more cumulative trauma, pervasive feelings of uncontrollability and passive coping strategies than controls. Moreover, the use of passive coping styles was positively associated with the accumulation of trauma and the expression of GI symptoms. Using hierarchical regression and mediation analyses, we found support for the sequential model postulating passive coping styles as (partial) mediators of trauma-induced (GI) disease manifestations. Specifically, out of all coping styles associated with cumulative trauma, behavioural disengagement most powerfully mediated the effect of trauma on GI symptom severity, accounting for 12% (IBD) to 14% (IBS) of its total effect. A somewhat smaller mediating role was observed for social support coping, the reduced reliance on which explained 7% (IBS) to 10% (IBD) of trauma's total effect. Finally, neuroticism acted as a channel through which past traumatization affected subjects' proneness to behavioural disengagement and, consequently, their GI disease activity.