Malabsorption is a term for any condition in which one or more essential nutrients or minerals are not properly digested or absorbed by the intestines. Lipids (fats) are the most commonly malabsorbed nutrients, but proteins, carbohydrates, electrolytes (such as sodium and potassium), vitamins and minerals (such as iron and calcium) may be poorly absorbed as well.
A multitude of different disorders can result in malabsorption; outlook depends upon the success in treating the underlying cause. Symptoms may range from bouts of gas, diarrhea and stomach cramps that occur only when certain foods are consumed and maldigested to emaciation and other signs of severe malnutrition.
What Causes Malabsorption?
- Any defect in the functioning of the digestive system (for example, an inadequate production of bile salts by the liver, or digestive enzymes by the pancreas, or cells lining the intestine, or damage to the intestinal absorptive cells) can prevent the proper breakdown of foods and the absorption of adequate amounts of nutrients.
- A major cause of malabsorption is chronic pancreatitis (often related to alcohol abuse), which may lead to decreased secretion of pancreatic enzymes that digest food—especially fats and protein.
- Inflammation or other abnormalities (Crohn’s Disease and Amyloidosis) in the mucous membrane that lines the intestine may prevent nutrients from being absorbed through the intestinal wall.
- Surgery to remove diseased segments of the intestine may result in an inadequate amount of absorptive surface. This is called short bowel syndrome.
- Infections (including acute infectious enteritis) and tapeworm or other parasites may inhibit proper digestion. Some infections may result in an overgrowth of intestinal bacteria, which may also lead to malabsorption. Those with AIDS are particularly prone to malabsorption, since the disease damages immune defenses against secondary infections that may cause digestive problems.
- Any obstruction of the lymphatic system, as may occur with lymphomas and tuberculosis, may also interfere with nutrient absorption.
- Certain cardiovascular problems may result in malabsorption (Congestive Heart Failure and Pericarditis).
- Certain medications may induce malabsorption. These medications include cholestyramine (a cholesterol-lowering drug), neomycin (an antibiotic), colchicine (an antigout drug), and certain laxatives.
- Other diseases, including diabetes mellitus, hyper- and hypothyroidism, and carcinoid syndrome, may cause malabsorption for reasons that are unclear.
- Diseases such as abetalipoproteinemia, AIDS, biliary atresia and celiac disease also cause malabsorption.
Symptoms of Malabsorption
- Stools that float and are bulky, greasy and unusually malodorous
- Excessive gas
- Abdominal discomfort or cramps, especially after eating
- Weight loss or emaciation
- Night blindness (vitamin A malabsorption)
- Easy bruising (vitamin K malabsorption)
- Bone pain and painful muscle contractions (calcium malabsorption)
- Paleness (pallor) and other symptoms of anemia
- High susceptibility to infection
- Muscle wasting
Prevention of Malabsorption
- Malabsorption is preventable only when the underlying cause (such as an infection) is preventable.
- Avoid drinking too much alcohol.
- When going to places with questionable water supply, drink only bottled water, eat only cooked foods, and avoid fresh salads or other washed produce.
- Limit use of certain medicines, such as antibiotics, that can adversely affect the function of the intestines.
- Do not use laxatives.
Diagnosis of Malabsorption
- Patient history, including use of alcohol and physical examination
- Blood tests for anemia and other nutritional deficiencies
- Stool samples looking for undigested fat.
- Culture of the microorganisms inhabiting the intestine.
- Breath tests to detect lactose intolerance or bacterial overgrowth in the small intestine.
- Biopsy of intestinal tissue (may be taken during endoscopy; that is, visual inspection of the upper small intestine with a flexible, lighted scope)
- Upper GI (gastrointestinal) and small bowel series (use of barium to create a clear image of the intestine on x-ray)
How to Treat Malabsorption
- In some cases the only treatment necessary is to avoid certain foods that trigger or exacerbate symptoms. For example, those with lactose intolerance should avoid milk products; those with nontropical sprue (celiac disease) may be cured by avoiding all foods containing gluten (a protein found in wheat, rye, oats and barley).
- The underlying disorder causing malabsorption must be diagnosed and treated. For instance, antibiotics are given to cure an infection.
- Nutritional supplements may be prescribed. Common supplements include calcium, magnesium, iron, and vitamins A, D, E, and K.
- Pancreatic enzymes may be prescribed to correct insufficient production of them.
- Corticosteroids may improve absorption in some cases of inflammatory diseases.
- In many cases a high carbohydrate, low-fat diet is recommended; it is easiest to digest and absorb.
- A sweat test (collection of sweat from the skin) may be performed to see if cystic fibrosis is present.
When to Call a Doctor
- Call a doctor if diarrhea or other digestive problems persist for longer than three days.
Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference
Simeon Margolis, M.D., Ph.D., Medical Editor
Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50
Updated by Remedy Health Media