Irritable bowel syndrome: Newer pharmacological agents acting on the gut

The objectives of this brief review are to provide an update on the clinical pharmacology and clinical trials of new potential therapies for irritable bowel syndrome (IBS). These medications include: 5-HT₃ antagonists, 5-HT₄ agonists, α₂-adrenergic agonists, κ opioid agonists, neurokinin antagonists, neostigmine, probiotics and antibiotics. While these approaches offer promise and a substantial rationale based on modulating the brain gut axis, the potential for central effects and the clinical efficacy of some of these agents are still being explored, and proof of concept studies needs to be supported by robust evidence of positive risk–benefit.