Malabsorption is difficulty absorbing nutrients from food.

Many diseases can cause malabsorption. Malabsorption is usually the inability to absorb certain sugars, fats, proteins, or vitamins from food. It can also involve a general malabsorption of food.

Some of the causes of malabsorption include:

• AIDS and HIV
• Biliary atresia
• Celiac disease
• Certain medications (cholestyramine, tetracycline, some antacids, some medications used to treat obesity, colchicine, acarbose, phenytoin)
• Certain types of cancer (lymphoma, pancreatic cancer, gastrinomas)
• Certain types of surgery (gastrectomy with gastrojejunostomy, surgical treatments for obesity, partial or complete removal of the ileum)
• Cholestasis
• Chronic liver disease
• Cow's milk protein intolerance
• Crohn's disease
• Damage from radiation treatments
• Parasite infection, including Giardia lamblia
• Soy milk protein intolerance
• Whipple's disease

Vitamin B12 malabsorption may be due to:

• Pernicious anemia
• Bowel resection
• Tapeworm infection (Diphyllobothrium latum)

• Bloating, cramping, and gas
• Bulky stools
• Chronic diarrhea (may not occur with vitamin malabsorption)
• Failure to thrive
• Fatty stools (steatorrhea)
• Muscle wasting
• Weight loss

Malabsorption can affect growth and development, or it can lead to specific illnesses.

• Blood and urine tests
• CT scan of the abdomen
• Hydrogen breath test
• Schilling test for vitamin B12 deficiency
• Secretin stimulation test
• Small bowel biopsy
• Stool culture or culture of small intestine aspirate
• Stool fat testing (See: Quantitative stool fat test)
• X-rays of the small bowel or other imaging tests

Vitamin and nutrient replacement is often necessary.

The outlook depends on the condition causing malabsorption.

Long-term malabsorption can result in:

• Anemia
• Gallstones
• Kidney stones
• Osteoporosis and bone disease
• Malnutrition and vitamin deficiencies

Call your health care provider if you notice symptoms of malabsorption.

Preventive methods depend on the condition causing malabsorption.

Semrad CE. Approach to the patient with diarrhea and malabsorption. In Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 142.

Hogenauer C, Hammer HF. Maldigestion and malabsorption. In: Feldman M, Friedman LS, Brandt LJ eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 101.