- Irritable bowel syndrome (IBS) is the most commonly diagnosed gastrointestinal condition manifested by chronic abdominal pain and altered bowel habits in the absence of any organic cause. While 10% - 20% of the population has IBS, only ≈ 25% of patients with IBS seek professional health care. Due to IBS multifactorial etiology, there is no single therapeutic option available with a satisfactory efficacy; therefore, patients frequently express a high level of frustration with their current therapies. We present a case of the 42 year-old woman with IBS, who was administered Omalizumab (a recombinant DNA-derived humanized IgG1 monoclonal antibody which specifically binds to free human immunoglobulin E (IgE) in the blood) doe to concomitant antihistamine resistant chronic spontaneous urticaria and experienced significant improvement in overall IBS symptoms. If our observation will be confirmed in prospective randomized studies, Omalizumab may turn out to be a useful pharmacological tool for this common disorder.