Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. People who have celiac disease cannot tolerate a protein called gluten, found in wheat, rye, and barley. When people with celiac disease eat foods or use products containing gluten, their immune system responds by damaging the small intestine. The tiny, fingerlike protrusions lining the small intestine are damaged or destroyed. Called villi, they normally allow nutrients from food to be absorbed into the bloodstream. Without healthy villi, a person becomes malnourished, regardless of the quantity of food eaten.
Coeliac disease or celiac disease is an autoimmune disorder of the small bowel that occurs in genetically predisposed individuals in all age groups after early infancy. Symptoms may include diarrhoea, failure to thrive (in children) and fatigue, but these may be absent and associated symptoms in all other organ systems have been described. It affects approximately 1% of Caucasian populations, though it is significantly underdiagnosed. A growing portion of diagnoses are being made in asymptomatic persons as a result of increasing screening.
Coeliac disease is caused by a reaction to gliadin, a gluten protein found in wheat (and similar proteins of the tribe Triticeae which includes other cultivars such as barley and rye). Upon exposure to gliadin, the body's immune system cross-reacts with the enzyme tissue transglutaminase, causing an inflammatory reaction that leads to flattening of the lining of the small intestine, which interferes with the absorption of nutrients. The only effective treatment is a diet, lifelong in principle, from which gluten is absent.
This condition has several other names, including: cœliac disease (with ligature), c(o)eliac sprue, non-tropical sprue, endemic sprue, gluten enteropathy or gluten-sensitive enteropathy, and gluten intolerance. The term coeliac derives from the Greek κοιλια (koilia, abdomen), and was introduced in the 19th century in a translation of what is generally regarded as an ancient Greek description of the disease by Aretaeus of Cappadocia.