Background. It has been speculated that asthma and irritable bowel syndrome may share common pathophysiological processes. Aim. To estimate the prevalence of irritable bowel syndrome in young and elderly patients with stable asthma. Patients and methods. Sixty-five young (age < 60 years) and 66 elderly (age ≥ 60 years) stable asthmatics, and 119 age-matched healthy volunteers were enrolled. In all participants, presence of irritable bowel syndrome, quality of life and psychological status were evaluated. Results. The prevalence of irritable bowel syndrome in asthmatic group was higher than that in the control group (27.5% versus 16.8%; odds ratio, 1.8 [1.0–3.4]; p = 0.04). The prevalence of irritable bowel syndrome was significantly higher in young asthmatics than in age-matched healthy controls (36.9% versus 20.3%; odds ratio, 2.2 [1.0–5.1]; p = 0.04) and than in elderly asthmatics (36.9% versus 18.2%; odds ratio, 0.3 [0.1–0.8]; p = 0.01). Logistic regression analysis identified the younger age (odds ratio, 2.1 [1.1–3.8]; p = 0.01), and the presence of asthma (odds ratio, 1.9 [1.0–3.5]; p = 0.03) as independent risk factors for irritable bowel syndrome in all participants after adjusting for gender. We also found impaired quality of life to be associated with the presence of irritable bowel syndrome and asthma in all participants after adjusting for age and gender. Conclusion. The prevalence of irritable bowel syndrome appears to be significantly higher in young asthmatics, but not in elderly asthmatics, compared to age-matched healthy counterparts. Potential pathogenic mechanisms of higher irritable bowel syndrome prevalence in young asthmatics need to be explained by further studies.