ABSTRACT
BACKGROUND: Irritable bowel syndrome (IBS) is associated with bronchial asthma. However, published data on airway resistance or impedance in patients with IBS but without any respiratory symptoms are lacking. METHODS: Patients with IBS but no respiratory symptoms underwent spirometry and airway resistance measurement using impulse oscillometry; the data were compared with those from 97 historical age- and sex-matched healthy control subjects. RESULTS: Patients had lower FEV1 (3.03 [0.74] vs. 3.35 [0.80] L/min; p=0.004) and FVC (3.56 [0.85] vs. 3.88 [0.9]; p=0.01) than healthy subjects; however, the values were within the normal range. Patients had a higher resistance at 5 Hz (0.45 [0.42] vs. 0.30 [0.15] kPa L/s; p=0.003); however, reactance at this frequency was not significantly different (-0.08 [0.30] vs. -0.10 [0.09] kPa L/s; p=0.438). CONCLUSION: Patients with IBS have increased airway resistance as compared to healthy subjects, as measured by impulse oscillometry; however, reactance is unchanged, indicating no change in elastic resistance.