Positive and negative affect mediate the bidirectional relationship between emotional processing and symptom severity and impact in irritable bowel syndrome

Introduction: Individuals with IBS report higher levels of psychological distress compared to healthy controls. Distress has been associated with emotional processing difficulties but studies have not explored how the relationship between distress and emotional processing affects IBS. There is little research on the role of positive affect (PA) in IBS.

Aims: (a) If difficulties in self-reported emotional processing are associated with affect and IBS measures (i.e., symptom severity, interference in life roles) (b1) If affect mediates the relationship between emotional processing and IBS measures (b2) Alternative model: if affect mediates the relationship between IBS and emotional processing (c) If PA moderates the relationship between distress and IBS.

Methods: Participants with a confirmed diagnosis of IBS (n=558) completed a questionnaire including measures of emotional processing (i.e., unhelpful beliefs about negative emotions, impoverished emotional experience), distress, PA, and IBS symptoms/interference. Mediation and moderation analyses were conducted with Maximum Likelihood Estimation.

Results: Distress and PA mediated or partly mediated the relationship between unhelpful beliefs about negative emotions/impoverished emotional experience and both IBS measures. The alternative models were also valid, suggesting a two-way relationship between emotional processing and IBS through affect. PA did not moderate the relationship between distress and IBS.

Conclusion: Future interventions in IBS may benefit from not only targeting the management of physical symptoms and their daily impact but also aspects related to the experience of both negative and positive affect, and the acceptance and expression of negative emotions. Longitudinal studies are needed to confirm causal relationships within the explored models.