Celiac disease is a disease characterized by permanent intolerance to gluten, a glycoprotein present in wheat, barley, rye and oats. It occurs in genetically predisposed individuals suffering from atrophy to the villi of the small intestine, making it difficult to absorb nutrients from some foods. Depending on the degree of intolerance, some other symptoms occur and it is possible that none of them is present. Still, the most common manifestations of this disease are gastrointestinal problems, iron deficiency and colitis. In cases where no apparent signs occur but is diagnosed through routine screening once to avoid eating gluten, the patient will experience a great improvement both physical and mental.