Definition

Malabsorption is difficulty absorbing nutrients from food.

Causes, incidence, and risk factors

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 disease

Vitamin B12 malabsorption may be due to:

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

Symptoms

• 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.

Signs and 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

Treatment

Vitamin and nutrient replacement is often necessary.

Expectations (prognosis)

The outlook depends on the condition causing malabsorption.

Complications

Long-term malabsorption can result in:

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

Calling your health care provider

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

Prevention

Preventive methods depend on the condition causing malabsorption.

References

Semrad CE, Powell DW. Approach to the patient with diarrhea and malabsorption. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 143.