Irritable bowel syndrome is a prevalent and chronic disorder, characterized by recurrent abdominal pain/discomfort, bloating and altered bowel habits. This condition affects an estimated 10-15% of the population worldwide and impacts heavily on a patient's daily life and ability to work, as well as healthcare resource utilization. Drug therapy aimed at correcting the primary symptoms of diarrhea/constipation/bloating may have little effect on abdominal pain, which results from visceral hypersensitivity. Smooth muscle relaxants or antispasmodics decrease the tone and contractility of intestinal smooth muscle, effectively managing abdominal pain. Otilonium bromide has been widely used worldwide and has been found to be safe and well tolerated, and superior to placebo for the reduction of symptoms and the prevention of symptom relapse in patients with irritable bowel syndrome.