Food sits at the intersection between gastrointestinal (GI) physiology and symptoms in patients with the irritable bowel syndrome (IBS). It is now clear that the majority of IBS sufferers associate eating a meal with their GI and non-GI symptoms. This is hardly surprising when one considers that food can affect a variety of physiologic factors (motility, visceral sensation, brain–gut interactions, microbiome, permeability, immune activation, and neuro-endocrine function) relevant to the pathogenesis of IBS. In recent years, clinical research has increasingly focused on diet as a treatment for IBS. There is a relative paucity of data from rigorous, randomized, controlled trials for any dietary intervention in IBS patients. Currently, the largest body of literature has addressed the efficacy of dietary restriction of fermentable oligo, di, monosaccharides, and polyols (FODMAPs). In the future, dietary treatments for IBS will move beyond the current focus on elimination to embrace supplementation with “functional” foods.