This article reviews the efficacy and tolerability of traditional therapies for irritable bowel syndrome (IBS) and concludes that they are limited by both poor efficacy and adverse effects. Serotonin, a neurotransmitter found mainly in the gut, appears to represent a link in IBS pathophysiological processes – altered gut motility, abnormal intestinal secretion and visceral hypersensitivity. Recently, available treatments for IBS have targeted serotonin receptors that are involved in motor, sensory and secretory functions of the gut. Serotonergic agents, such as alosetron (a 5‐HT₃ receptor antagonist) and tegaserod (a selective 5‐HT₄ receptor partial agonist), provide global relief of the multiple symptoms of IBS with diarrhoea and IBS with constipation, respectively, and represent important additions to the IBS treatment armamentarium.