Rectal tone and brain information processing in irritable bowel syndrome

We studied differences, in rectal tone between healthy controls, nonpsychia tric irritable bowel syndrome (IBS) patients, and IBS patients with comorbi d phobic anxiety disorders to assess the impact of psychiatric comorbidity on rectal tone. The groups were additionally compared with respect to brain information processing of everyday words with emotional content to see if we could identify an association between perception of emotional material i n the brain and rectal tone. We found that both nonpsychiatric IBS patients and IBS patients with phobic anxiety disorder had increased baseline recta l tone compared with healthy controls (F = 9.81, P < 0.001). The phobic anx iety patients tended to have increased tone compared with nonpsychiatric IB S patients, but the difference did not reach statistical significance. Simi lar differences were found in the attentional elements of brain information processing activity assessed by event-related potentials. Rectal tone sign ificantly predicted brain reactivity to emotional words, suggesting that ch anges in intestinal motor function may influence brain perception.