Background: Despite the known systemic manifestations of inflammatory bowel disease (IBD) and a large number of reports associating lung disease and IBD, the frequency of atopy and bronchial hyperreactivity (BHR) in IBD remains obscure. Objectives: The aim of this study was to investigate the prevalence of abnormal pulmonary function tests, BHR and the atopic status in patients with IBD. Methods:Thirty patients with IBD (19 with ulcerative colitis and 11 with Crohn's disease; 19 male, 11 female) and 16 controls without any gastrointestinal disease (9 female, 7 male) were included. Patients were questioned with respect to pulmonary and allergic symptoms; subsequently, lung function tests, BHR, skin prick test positivity, peripheral eosinophilia and serum IgE levels were evaluated and compared with those of control subjects. Results: The mean duration of IBD was 5.3 +/- 4.8 years. IBD patients had significantly more often respiratory symptoms in comparison with controls (odds ratio, OR: 9.0, p < 0.04). A previous diagnosis of asthma and antiasthmatic drug treatment were noted in 3/30 (10%) IBD patients. Allergic symptoms were more prevalent in IBD patients in comparison with the controls (OR: 13, p < 0.007), particularly in patients with ulcerative colitis (OR: 16, p < 0.004). The mean FEV1 was 3.1 +/- 0.9 liters (96 18% predicted), mean methacholine PD20:14.7 +/- 3.6 mg/ml, mean IgE: 190.5 +/- 305.6 IU/ml (normal value <94 IU/ml) and the percentage of peripheral eosinophils was 3.1 +/- 3.3% in the IBD patients. These values did not result in statistically significant differences in comparison with controls. Furthermore, abnormal lung function and BHR were observed in 8/30 (27%) and 5/30 (17%) IBD patients, respectively. Abnormal lung function tests were more prevalent in the IBD patients than in the controls (OR: 12, p < 0.04). Skin prick tests were positive in 15/30 (50%) IBD patients. The risk of a positive skin prick test increased in the IBD patients in comparison with the controls (OR: 7.0, p < 0.02). Duration and activity of IBD did not influence the prevalence of BHR, allergic and respiratory symptoms, abnormal lung function, high serum IgE levels and skin test positivity. Conclusions: Allergic symptoms, respiratory symptoms, abnormal lung function tests and skin prick test positivity were more common among the IBD patients in comparison with the controls. Copyright (C) 2003 S. Karger AG, Basel.