Malabsorptionsstörungen

Malabsorption refers to impaired absorption of nutrients from the small intestine, due to mucosal disease, luminal factors, or postoperative changes. It can affect fats, carbohydrates, proteins, vitamins, and minerals, leading to nutritional deficiencies and gastrointestinal symptoms.

Common causes include mucosal diseases such as celiac disease, Crohn's disease, and tropical sprue; pancreatic exocrine insufficiency from chronic pancreatitis; bile acid malabsorption; small intestinal bacterial overgrowth; infections such as Giardia; and anatomic loss from bowel resection or short bowel syndrome.

Clinical features vary; typical presentations include chronic diarrhea, bulky pale or oily stools (steatorrhea), weight loss, and abdominal bloating. Symptoms reflect the type and extent of nutrient loss, and signs of vitamin or mineral deficiencies may develop in prolonged cases.

Evaluation usually begins with history and examination, followed by stool studies to quantify fat excretion, tests of pancreatic function (fecal elastase), and serologic testing for celiac disease. Breath tests can assess carbohydrate malabsorption, while upper endoscopy with mucosal biopsy confirms mucosal disease. Imaging and nutritional assessment help identify structural lesions and guide supplementation.

Treatment targets the underlying cause and nutritional support. Dietary changes may include reduced long-chain fat intake or use of medium-chain triglycerides; pancreatic enzyme replacement for pancreatic insufficiency; lactase supplements for lactose intolerance; antibiotics for bacterial overgrowth; and vitamin and mineral supplementation. In severe cases, parenteral nutrition or surgical management may be required.

Prognosis depends on the cause and response to therapy; early diagnosis and individualized management improve symptoms and prevent deficiencies.