Dietary exclusion of gluten-containing products has become increasingly popular in the general population, and currently ∼30% of people in the United States are limiting gluten ingestion. Although celiac disease (CD), wheat allergy (WA), and nonceliac gluten sensitivity (NCGS) constitute a spectrum of gluten-related disorders that require exclusion of gluten from the diet, together these account for a relatively small percentage of those following a gluten-free diet, and the vast majority has no medical necessity for doing so. Differentiating between CD, WA, and NCGS has important prognostic and therapeutic implications. Because of the protean manifestations of gluten-related disorders, it is not possible to differentiate between them on clinical grounds alone. This clinical report will compare and contrast the manifestations of gluten-related disorders, emphasize the importance of differentiating between these conditions, discuss initial and subsequent tests needed to confirm the diagnosis, and provide recommendations on treatment and follow-up for each condition.