The pathophysiology of irritable bowel syndrome (IBS) has not yet been fully elucidated. We reviewed articles addressing IBS that have been published in the last 2 years and selected papers related to IBS pathophysiology and treatment. Studies of intestinal bacteria, low-grade mucosal inflammation, and increased mucosal permeability-factors involved in the pathophysiology of IBS-have been conducted. In addition, the involvement of intestinal bacteria in IBS pathology has been clarified; many studies of treatments related to intestinal bacteria have been reported. Moreover, several studies address the effect on IBS of antidepressants and psychotherapy through the brain-gut axis. The contents of these papers are described in this narrative review.
Keywords: Irritable bowel syndrome; antidepressant; intestinal bacteria; mucosal inflammation; mucosal permeability; pathophysiology; psychotherapy; treatment.