Functional gastrointestinal disorders are the most common gastroenterological problem in our society. Changes in gut function, including pain perception, motility, and intestinal permeability, and low-grade inflammation have been described in patients with irritable bowel syndrome (IBS). The triggering factors for the described immunity and gut functional changes in patients with IBS are not completely understood. Similarly to post-infective IBS, some patients with IBS symptoms exhibit immunological evidence of gluten sensitivity but have no overt intestinal mucosal injury. They have symptoms that meet the diagnostic criteria for IBS and respond symptomatically to exclusion of gluten from the diet. Thus, gluten sensitivity may be involved in the pathogenesis of a subgroup of IBS patients. Unfortunately, there remain many unanswered questions regarding the mechanistic link between gluten sensitivity and functional gastrointestinal symptoms.