Recent advances in research on irritable bowel syndrome (IBS) largely clarified pathophysiological mechanism including brain-gut interactions, gastrointestinal motility, visceral perception, gut immune system, gut microbiota, genetics, biomarkers, and psychosocial factors. In this symposium, audience will understand the new development of IBS research and evidence of IBS treatment. To date, the following agents and treatments for IBS are developing. They are 5-HT4 receptor agonists, 5-HT3 receptor antagonists, tryptophan hydroxylase 1 blocker, ClC-2 channel activator, guanylate cyclase-C agonist, proteinase-activated receptor 2 blockers, TRPV1, 4 blockers, mast cell stabilizers, μ-opioid receptor agonists, μ-opioid receptor antagonists, κ-opioid receptor agonists, β3-adrenoceptor agonists, α2-adrenoceptor agonists, neurokinin receptor 1-3 antagonists, corticotropin-releasing hormone receptor antagonists, cholecystokinin receptor 1 antagonists, bile acid, bile acid binder, antibiotics, probiotics, antidepressants, kampo medicine, diet therapy, exercise, stress management, hypnotherapy, and cognitive behavior therapy. Furthermore, new insight for IBS treatment will be discussed.