American Gastroenterological Association (AGA) Institute Technical Review on the Diagnosis and Management of Celiac Disease

Celiac disease is a unique disorder that is both a food intolerance and autoimmune disorder. Celiac disease can be defined as a permanent intolerance to the storage proteins from wheat rye and barley, herein after referred to as "gluten." It is characterized by a chronic inflammatory state of the proximal small intestinal mucosa that heals when foods containing gluten are excluded from the diet and returns when these foods are reintroduced. Complex adaptive and innate immune reactions result in chronic inflammation of the mucosa and a panoply of structural and functional changes. There is atrophy of the small intestinal villi, deepening of the crypts, and infiltration of the lamina propria and intraepithelial compartments with chronic inflammatory cells. The functional changes include decreased digestion of food, decreased absorption of macronutrients and micronutrients, and increased net secretion of water and solute. Other consequences of chronic inflammation such as ulceration or stricturing may occur, although much less frequently. Extraintestinal manifestations affect many organ systems.