AIM: To correlate the clinical features of treated and untreated patients with irritable bowel syndrome (IBS) to the results of skin prick test (SPT) for food and inhalant allergens. METHODS: We recruited 105 subjects to form three different target groups: treated group (n=44) undergoing treatment for IBS, untreated group (n=31) meeting the RomeⅡcriteria without treatment for IBS, control group (n=30) with no IBS symptoms. RESULTS: SPT results were different among the three groups in which SPT was positive in 17 (38.6%) treated patients, in 5 (16.1%) untreated patients and in 1 (3.3%) control (P<0.01). The number of positive SPTs was greater in the IBS group than in the control group (P< 0.001). The number of positive food SPTs was higher in the treated IBS group than in the untreated IBS group (P=0.03). CONCLUSION: Positive food SPT is higher in IBS patients than in controls. AIM: To correlate the clinical features of treated and untreated patients with irritable bowel syndrome (IBS) to the results of skin prick test (SPT) for food and inhalant allergens. METHODS: We recruited 105 subjects to form three different target groups: treated group (n = 44) undergoing treatment for IBS, untreated group (n = 31) meeting the Rome II condition without treatment for IBS, control group (n = 30) with no IBS symptoms. RESULTS: SPT results were different among the three groups in which SPT The number of positive SPTs was greater in the IBS group than in the control group (16.1%) untreated patients and in 1 (3.3%) control (P <0.01) P <0.001). The number of positive food SPTs was higher in the treated IBS group than in the untreated IBS group (P = 0.03). CONCLUSION: Positive food SPT is higher in IBS patients than in controls.