Differences in somatic perception in female patients with irritable bowel syndrome with and without fibromyalgia

Background: Irritable bowel syndrome (IBS) and fibromyalgia (FM) an conside red chronic syndromes of altered visceral and somatic perception, respectiv ely. Because there is a significant overlap of IBS and FM, shared pathophys iological mechanisms have been suggested. Although visceral perception has been well studied in IBS, somatic perception has npt. Aims: To compare hype rvigilance and altered sensory perception in response to somatic stimuli in patients with IBS, IBS + FM, and healthy controls. Methods: Eleven IBS fem ales (mean age 40), 11 IBS + FM females (mean age 46), and ten healthy fema le controls (mean age 39) rated pain perception in response to pressure sti muli administered to active somatic tender points, non-render control point s and the T-12 dermatome, delivered in a predictable ascending series, and delivered in an unpredictable randomized fashion (fixed stimulus). Results. Although IBS patients had similar pain thresholds during the ascending ser ies compared with controls, they were found to have somatic hypoalgesia wit h higher pain thresholds and lower pain frequency and severity during fixed stimulus series compared with IBS + FM patients and controls (P < 0.05), P atients with IBS + FM were more bothered by the somatic stimuli and had som atic hyperalgesia with lower pain thresholds and higher pain frequency and severity. Conclusions: Both hypervigilance and somatic hypoalgesia contribu te to the altered somatic perception in IBS patients. Co-morbidity with FM results in somatic hyperalgesia in IBS patients. (C) 2000 International Ass ociation for the Study of Pain. Published by Elsevier Science B.V.