Malabsorption occurs when a person's body fails to receive the nutrients it needs from foods that are eaten. It can involve a particular type of nutrient or all nutrients (e.g., fats, carbohydrates, protein, vitamins and minerals).

Malabsorption may result from a disruption of any part of the digestive process within the small intestine. This includes problems with the chemical breakdown of food, absorption of nutrients through the intestinal wall and the transport of nutrients into the bloodstream.

Malabsorption may produce a variety of symptoms based on the type of deficiency present and its cause. For example, problems digesting fats can be caused by poor functioning of the pancreas and lead to steatorrhea (fat buildup in stool). Other symptoms of malnutrition may include diarrhea, anemia and unexplained weight loss, among others.

Diagnosis of malabsorption may include a physical examination and medical history. Certain fecal tests and blood tests can help detect the problem and additional testing may be necessary to determine the cause.

Almost 200 different conditions or diseases are associated with malabsorption. Some of these, such as cystic fibrosis and cancer, cause a number of other problems in addition to malabsorption. Others, such as lactose intolerance and short bowel syndrome, primarily involve malabsorption. Conditions that involve malabsorption may be referred to as malabsorption syndromes.

Treatment and prevention of malabsorption will depend on the type, cause and severity of the condition. Some treatment options include medications, nutritional supplements, and intravenous feeding (total parenteral nutrition).