Attentional Biases in Irritable Bowel Syndrome Patients: The Role of Interoception and Anxiety

Irritable bowel syndrome (IBS) is considered a disorder of brain-gut interaction. Central processes like selective attention to visceral stimuli are involved in the pathophysiology of IBS. The primary aim of this study was to replicate the Tkalčić and colleagues' experiment using the same modified Stroop task to assess the reliability of previously obtained results. A secondary objective was to explore the proposed associations between attentional indices and various aspects of anxiety and interoceptive accuracy.

Ninety IBS patients and 77 healthy controls (HC) completed a set of questionnaires [State-Trait Anxiety Inventory (STAI-T), Visceral Sensitivity Index (VSI), Anxiety Sensitivity Index (ASI) and Anxious Thoughts Inventory (ATI)] followed by a heartbeat counting task and an emotional Stroop task.

Repeated measures 2-way ANOVA showed no significant effects. GLMM results showed that IBS patients had shorter RTs (~50 ms) than HCs. The IBS group scored higher than HC in all anxiety measures, while there were no differences in IAcc. Positive correlations were found among all anxiety measures in both groups. There was a negative correlation of average RT with ASI, ATI, and IAcc, only in the IBS group. IBS patients with higher ASI and ATI have faster RTs, while patients with higher IAcc have lower RTs.

Stroop facilitation was not replicated, but IBS patients were faster than HCs. This study provides preliminary evidence that IBS patients may show distinct attentional patterns, marked by a general tendency for faster engagement, independent of stimulus type. This effect may relate to higher interoceptive accuracy and anxiety, and was not observed in HCs.