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. These nutrients can be macronutrients (proteins, carbohydrates, and fats), micronutrients (vitamins and minerals), or both.
Many things can lead to malabsorption syndrome, from certain diseases to infections or birth defects.
Factors that may cause malabsorption syndrome include:
- damage to the intestine from infection, inflammation, trauma, or surgery
- prolonged use of antibiotics
- other conditions such as celiac disease, Crohn’s disease, chronic pancreatitis, or cystic fibrosis
- lactase deficiency, or lactose intolerance
- certain defects that are congenital (present at birth), such as biliary atresia (when the bile ducts don’t develop normally and prevent the flow of bile from the liver)
- diseases of the gallbladder, liver, or pancreas
- parasitic diseases
- radiation therapy, which may injure the lining of the intestine
- certain drugs that may injure the lining of the intestine, such as tetracycline, colchicine, or cholestyramine
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.
There are also some uncommon disorders that can result in malabsorption. One of these is called short bowel syndrome (SBS). With this condition, the small intestine is shortened. This makes the intestine less able to absorb nutrients. SBS may be a birth defect, or it may be caused by surgery.
Certain diseases may cause malabsorption. These include tropical sprue, a condition most common in the Caribbean, India, and other parts of Southeast Asia. This disease may be related to environmental factors, such as toxins in food, infection, or parasites. An even rarer potential cause of malabsorption is Whipple’s disease, which is a result of a bacterial infection.
Symptoms of malabsorption syndrome are caused 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. For instance, you may have the following symptoms if you’re unable to absorb fats, protein, or certain sugars or vitamins:
- Fats: You may have light-colored, foul-smelling stools that are soft and bulky. Stools are difficult to flush and may float or stick to the sides of the toilet bowl.
- Protein: You may have dry hair, hair loss, or fluid retention. Fluid retention is also known as edema, and will manifest as swelling.
- Certain sugars: You may have bloating, gas, or explosive diarrhea.
- Certain vitamins: You may have anemia, malnutrition, low blood pressure, weight loss, or muscle wasting.
Malabsorption may affect people based on age or gender. For instance, women 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 gender. Another sign of malabsorption in children is that they may purposefully avoid certain foods.
Risk factors for malabsorption syndrome include:
- a family history of cystic fibrosis or malabsorption
- drinking large amounts of alcohol
- intestinal surgery
- use of certain medications, including laxatives or mineral oil
- travel to the Caribbean, India, and other parts of Southeast Asia
Your doctor may suspect malabsorption syndrome if you have chronic diarrhea or nutrient deficiencies, or have lost a significant amount of weight despite eating a healthy diet. Certain tests are used to confirm the diagnosis. These tests may include:
Stool tests can measure fat in samples of stool (feces). These tests are the most reliable because fat is usually present in the stool of someone with malabsorption syndrome.
These tests measure the level of specific nutrients in your blood, such as vitamin B-12, vitamin D, folate, iron, calcium, carotene, phosphorus, albumin, and protein. A lack of one of these nutrients may not necessarily mean you have malabsorption syndrome. It can mean you are not choosing foods with healthy levels of nutrients. Normal levels of these nutrients suggest that malabsorption is not the problem.
Breath tests can be used to test for lactose intolerance. If lactose is not 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 will 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, which take pictures of your digestive system, may be done to look for structural problems. For instance, a CT scan may be done to look for thickening of the wall of your small intestine, which could be a sign of Crohn’s disease.
You may have a biopsy if your doctor suspects that you have abnormal cells in the lining of your small intestine. This test 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, where it takes a small sample of cells.
Your doctor will likely start your treatment by addressing symptoms such as 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. And they may monitor you for signs of dehydration, which can include increased thirst, low urine output, and dry mouth, skin, or tongue.
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 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 increase foods high in potassium to help balance your electrolytes.
Your doctor and your dietitian can help create a treatment plan that will manage your malabsorption symptoms and allow your body to obtain the nutrients and fluids it needs to function normally.