the small intestine has an inner lining of cells that form finger-like projections called villi. the villi are important because they increase the number of cells and surface area available for the absorption of nutrients from the intestinal lumen into the bloodstream. in celiac disease inflammation destroys the villi causing the inner lining of the small intestine to become flattened. this loss of villi reduces the cells and surface area available for absorption of nutrients. the impaired absorption of nutrients is referred to as malabsorption. the malabsorption of nutrients leads to nutrient deficiencies referred to as malnutrition. the length (amount) of the small intestine affected by the loss of villi varies from patient to patient and the length that is involved determines the severity of signs and symptoms. thus patients whose entire small intestine is affected by a loss of villi have more severe signs and symptoms of malabsorption than patients who have only part of the small intestine affected. when only part of the small intestine is affected it usually is the upper small intestine (the duodenum and jejunum) that is more affected than the lower small intestine (the ileum).
what does celiac disease do to the small intestine?