Irritable Bowel Syndrome and Bronchial Hyperresponsiveness: Is There a Link?

Abstract

Background/Aim: Many studies have demonstrated a high prevalence of bronchial hyperresponsiveness in patients with irritable bowel syndrome (IBS). The aim of this 24-month prospective study was to evaluate the prevalence of IBS in asthmatic patients. Methods: We analyzed 623 asthmatic patients that were evaluated for body mass index, sex, and age before undergoing both a methacholine challenge test (MCHt) and skin prick tests. Results: We found that 276 asthmatic patients (44.3%) were positive on the MCHt, while 347 (55.7%) were negative. We also found that 27 (9.7%) of the 276 patients with a positive MCHt and 44 (12.7%) of the 347 patients with a negative MCHt were affected by IBS. Therefore, there was no statistically significant difference between positive MCHt tests and IBS. The PC₂₀ (mean provocation concentration of methacholine producing a 20% reduction in forced expiratory volume in 1 s ≤16 mg/ml) in all patients tested was 8.64 ± 2.58 mg/ml, being 8.75 ± 2.52 and 8.55 ± 2.32 mg/ml for males and females, respectively. Conclusions: These results do not demonstrate a relationship between MCHt and IBS. However, a relationship might still exist in a subpopulation of patients whose symptoms worsen by stress.