Malabsorption syndrome is defined by the signs and symptoms produced by the nutritional deficiency which responds to the inappropriate absorption of nutrients in the bowel (proteins, fats, carbohydrates, vitamins and minerals). Its clinical presentation depends on the amount of intestinal surface affected and the physiopathologic mechanisms involved, which both determine the nutrient malabsorption. The most frequent symptoms are massive diarrhoea, weight loss and abdominal pain. There are several functional tests and radiological findings that suggest the diagnosis and the biopsy is characteristic. The aim of the treatment is to solve the cause of malabsorption, replace the nutrient deficiencies and treat the diarrhoea.