The main role of your small intestine is to absorb nutrients from the food you eat into your bloodstream. Malabsorption syndrome refers to a number of disorders in which the small intestine can’t absorb enough of certain nutrients and fluids.

Nutrients that the small intestine often has trouble absorbing can be one or both of the following:

  • macronutrients (proteins, carbohydrates, and fats)
  • micronutrients (vitamins and minerals)

Many things can lead to malabsorption syndrome, from certain diseases to infections or developmental issues.

Possible causes

Factors that may cause malabsorption syndrome include:

The syndrome may also be caused by digestive problems. Your stomach may not be able to produce the enzymes it needs to digest certain foods. Or, your body may not be able to mix the food you eat with the enzymes and acid produced by your stomach.

Rare causes

There are also some uncommon disorders that can result in malabsorption. One of these is called short bowel syndrome (SBS).

With SBS, the small intestine is shortened. This makes the intestine less able to absorb nutrients. SBS may be an irregularity present from birth, or it may be caused by surgery.

Certain diseases may cause malabsorption. These include tropical sprue, a condition most common in:

  • the Caribbean
  • India
  • parts of Southeast Asia

Tropical sprue may be related to environmental factors, such as:

An even rarer potential cause of malabsorption is Whipple’s disease, which is a result of a bacterial infection.

Symptoms of malabsorption syndrome occur when unabsorbed nutrients pass through the digestive tract.

Many symptoms differ depending on the specific nutrient or nutrients that are not being absorbed properly. Other symptoms are a result of a deficiency of that nutrient, which is caused by its poor absorption.

You may have the following symptoms if you’re unable to absorb fats, protein, or certain sugars or vitamins:

Malabsorption may affect people based on different characteristics. For instance, people may stop menstruating, and children may not grow properly. Their weight or rate of weight gain may be significantly below that of other children of a similar age and biological sex.

Another sign of malabsorption in children is that they may avoid certain foods.

Risk factors for malabsorption syndrome include:

A doctor may suspect malabsorption syndrome if you have:

Certain tests are used to confirm the diagnosis. These tests may include:

Stool tests

Stool tests can measure fat in samples of stool, or feces. These tests are the most reliable because fat is usually present in the stool of someone with malabsorption syndrome.

Blood tests

These tests measure the levels of specific nutrients in your blood, such as:

A lack of one of these nutrients may not necessarily mean you have malabsorption syndrome. It can mean you’re not choosing foods with enough nutrients.

Normal levels of these nutrients suggest that malabsorption is not the problem.

Breath tests

Breath tests can be used to test for lactose intolerance.

If lactose isn’t being absorbed, it enters the colon. Bacteria in the colon break down the lactose and produce hydrogen gas. The excess hydrogen is absorbed from your intestine into your bloodstream and then into your lungs. You’ll then exhale the gas.

If you have hydrogen gas in your breath after ingesting a product containing lactose, you may have lactose intolerance.

Imaging tests

Imaging tests, which take pictures of your digestive system, may be done to look for structural problems. For instance, your doctor could request a CT scan to look for thickening of the wall of your small intestine, which could be a sign of Crohn’s disease.

Biopsy

You may have a biopsy if your doctor suspects you have abnormal cells in the lining of your small intestine.

A biopsy will likely be done using an endoscopy. A tube is inserted into your mouth and sent through your esophagus and stomach and into your small intestine to take a small sample of cells.

Your doctor will likely start your treatment by addressing symptoms like diarrhea. Medications such as loperamide can help.

Your doctor will also want to replace the nutrients and fluids that your body has been unable to absorb. They may monitor you for signs of dehydration, which can include:

Next, your doctor will provide care based on the cause of the absorption problem. For instance, if you’re found to have lactose intolerance, your doctor will likely advise you to avoid milk and other dairy products or take a lactase enzyme tablet.

At this point, your doctor may refer you to a dietitian. Your dietitian will create a treatment plan that will help make sure you’re getting the nutrients your body needs. Your dietitian may recommend:

  • Enzyme supplements. These supplements can help your body absorb the nutrients that it can’t absorb on its own.
  • Vitamin supplements. Your dietitian may recommend high doses of vitamins or other nutrients to make up for those that are not being absorbed by your intestine.
  • Diet changes. Your dietitian may adjust your diet to increase or decrease certain foods or nutrients. For instance, you may be advised to avoid foods high in fat to decrease diarrhea and consume more foods high in potassium to help balance your electrolytes.

A doctor and dietitian can help create a treatment plan that will manage your malabsorption symptoms and allow your body to get the nutrients and fluids it needs to function properly.

Q:

What are the long-term complications of malabsorption syndrome?

Anonymous patient

A:

The complications of malabsorption depend upon the severity of the underlying condition. It can cause malnutrition, weight loss, impaired wound healing, immune system deficiency, and fatigue.

Judith Marcin, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.