Abstract
Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder characterized by abdominal pain associated with changes in stool consistency or bowel movement frequency. It is a highly prevalent chronic relapsing disorder that substantially impairs patients' quality of life and elevates societal healthcare costs. The low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet has emerged as a cornerstone dietary intervention for IBS owing to its demonstrated efficacy in alleviating symptoms. This article systematically reviews the progress in understanding the mechanism of the low FODMAP diet in the treatment of IBS, covering key dimensions such as reduced intestinal gas production, osmotic regulation, gut microbiota balance, abnormal intestinal fermentation, intestinal inflammatory and immune activation, and improvement in the gut-brain axis function. Additionally, this article reviews predictors of treatment response and outlines future research priorities based on recent evidence.