PURPOSE OF REVIEW: The role of gluten and wheat in irritable bowel syndrome (IBS) is unclear, whereas it plays a key-role in the diagnosis and treatment of noncoeliac gluten or wheat sensitivity (NCGWS). This review aims to provide the most recent insights in pathophysiological mechanisms and to summarize the evidence for a gluten- or wheat-free diet in IBS and NCGWS. RECENT FINDINGS: The exact role of gluten and wheat in IBS and NCGWS pathophysiological mechanisms remains complex. However, recent findings suggest a role for antigliadin antibodies to identify those IBS patients who may benefit from a gluten-free diet and low levels of fecal calprotectin to differentiate IBS and NCGWS. The importance of gut-brain interactions in self-reported gluten sensitive individuals was shown by a strong nocebo effect, although a role of gluten could not be excluded. Evidence for a gluten-free diet remains debatable in both conditions, whereas a wheat-free diet may have more potential, especially in NCGWS. SUMMARY: IBS and NCGWS are two closely related conditions with a complex and largely unrevealed pathophysiology. The role of gluten may have been overestimated in the past, but it is likely that certain wheat components, along with gut-brain interactions, play a role in both conditions.