Malabsorption
Malabsorption is a digestive disorder where your small intestine cannot properly absorb the nutrients, vitamins, and minerals from the food you eat into your bloodstream, potentially leading to nutritional deficiencies and various health complications.
Table of contents
- What is malabsorption?
- What causes malabsorption?
- Different types of malabsorption
- Signs and symptoms
- Possible complications
- How doctors diagnose malabsorption
- Treatment approaches
What is malabsorption?
Your small intestine plays a crucial role in absorbing essential nutrients from the food you eat. When you have malabsorption, your small intestine cannot properly take in nutrients from food into your bloodstream.[1] This can affect your ability to absorb one or more types of nutrients, including proteins, fats, carbohydrates, vitamins, and minerals.[3]
The process of digestion can be thought of as having three parts. The first part breaks down food into digestible pieces. The second part absorbs all the nutrients from your food. The third part eliminates the waste that is left over. Malabsorption disorders affect the second stage of this process.[8]
Although malabsorption and maldigestion (impaired breakdown of food) differ, digestion and absorption are interdependent, and the term “malabsorption” often refers to problems in either process.[2]
What causes malabsorption?
Malabsorption can result from problems in two main areas: food not being digested properly, or your intestines not being able to absorb nutrients.[3]
Several medical conditions can interfere with normal nutrient absorption. Infections from bacteria, viruses, or parasites can damage your intestinal wall so that digested substances cannot get through. You then lose those nutrients through your stool.[4]
Common causes of malabsorption include:[1][4]
- Celiac disease – when gluten protein triggers your immune system to attack your body
- Lactose intolerance – difficulty digesting milk sugar
- Short bowel syndrome – when part of the small intestine has been surgically removed
- Whipple disease – a rare bacterial infection
- Crohn’s disease and other inflammatory bowel diseases
- Cystic fibrosis, chronic pancreatitis, and other diseases affecting the pancreas
- Diseases caused by parasites, such as giardiasis or worms
- Changes in the bacteria normally found in the intestinal tract
- Certain medications, including some antibiotics, antacids, and medicines used to treat obesity
- Severe congestive heart failure, which causes the bowel wall to become swollen with fluid and prevents proper nutrient absorption
Your pancreas produces enzymes that help absorb fats and other nutrients. A decrease in these enzymes makes it harder to absorb fats and certain nutrients. Problems with your pancreas may be caused by trauma, infection, swelling, or surgery to remove part of the organ.[10]
Different types of malabsorption
Some gastrointestinal diseases cause general malabsorption of all kinds of nutrients. In other cases, you may have particular difficulties absorbing a specific kind of nutrient.[8]
Carbohydrate malabsorption
Some people are sensitive to one or several carbohydrates (sugars). You may experience this primarily as gas pain and abdominal bloating. Carbohydrates that are not fully absorbed in your small intestine get fermented by bacteria in your colon. The bacteria break them down into gases and short-chain fatty acids. The gases cause intestinal gas, and the short-chain fatty acids cause fatty stools.[8]
Fat malabsorption
This is a common type of malabsorption. Fats that are not absorbed in your small intestine pass to your colon, causing fatty stools (steatorrhea). Fatty stools are greasy and runny and particularly smelly. They may be light-colored and float.[8] Fat malabsorption also leads to the malabsorption of fat-soluble vitamins (A, D, E and K).[8]
Bile acid malabsorption
Sometimes fat malabsorption results from a lack of bile from diseases of the gallbladder, bile ducts, or liver. Leftover bile salts trigger your colon to secrete water, causing chronic diarrhea.[8]
Protein malabsorption
Protein malabsorption does not usually occur by itself unless you have a particular intolerance, such as milk protein intolerances or gluten intolerance.[8]
Signs and symptoms
The most common symptom of malabsorption is chronic diarrhea. You will have lots of loose, oily stools that smell worse than usual.[3]
Other symptoms may include:[3][4]
- Feeling gassy and bloated
- Losing weight
- Bad-smelling and loose stool
- Stools that are light in color or bulky
- Stools that are hard to flush away because they float or stick to the toilet bowl
- Weakness
- For women, stopped periods
Whatever you cannot absorb will pass undigested in your stools. People with malabsorption syndrome often have diarrhea as a side effect, which can make malabsorption worse. With diarrhea, food moves too fast through your bowels for nutrients to be absorbed.[8]
In children, malabsorption can cause weight loss or poor weight gain, often called failure to thrive. The child may not grow and develop normally. Adults may also have failure to thrive, with weight loss, muscle wasting, weakness, and even problems thinking.[10]
Vitamin and mineral deficiencies can cause additional symptoms, including:[3]
- Low blood count (anemia)
- Easy bruising
- Tingling of hands and feet
Possible complications
If your body is not getting the vitamins, minerals, and other nutrients it needs to stay strong and thrive, you could have serious complications.[4]
Over time, your body will start to show signs of deficiency in those nutrients that you cannot absorb. Deficiencies in any of the macronutrients (protein, fats, or carbohydrates) will cause signs of undernutrition, such as muscle wasting and reduced immunity. Deficiencies in micronutrients (vitamins and minerals) may affect your eyes, bones, skin, and hair.[8]
When it is not treated, malabsorption syndrome might lead to:[4]
- Greater chance of infections
- Osteoporosis (low bone density), which increases risk of bone fractures
- Slower growth and weight gain in children
Certain nutrients, such as vitamin A and zinc, are vital for a healthy immune system and proper growth. If your body is not absorbing these and other important vitamins and minerals, your health can suffer.[4]
Long-term malabsorption can also result in anemia, gallstones, kidney stones, and thin and weakened bones.[10]
How doctors diagnose malabsorption
Doctors usually perform stool tests to look for unabsorbed fat and blood tests to check for vitamin and mineral deficiencies.[3]
If these tests show malabsorption, doctors then do tests to look for the cause. They may:[3]
- Look down your stomach and intestines with a flexible viewing scope (endoscopy)
- Do breath tests
- Take x-rays after you swallow a liquid contrast agent
Additional tests your doctor may use include:[1][10]
- CT scan of the abdomen
- Small bowel biopsy
- Stool culture
- Stool fat testing
- Xylose testing
- Lower GI series (barium enema)
- Stool elastase test
Treatment approaches
Treatment depends on the cause of malabsorption. Two basic principles underlie management: correcting nutritional deficiencies and, when possible, treating the underlying disease causing the problem.[11]
Nutritional support
Caloric and protein replacement is essential. It is crucial to supplement with various minerals, such as calcium, magnesium, iron, and vitamins, which may be deficient in malabsorption.[11]
If you have trouble with only certain foods, doctors will have you avoid them. If you are missing certain digestive enzymes, sometimes you can take enzyme supplements. If you have a vitamin deficiency, you will take extra vitamins.[3]
- A special diet tailored to your specific needs
- Medicine to replace intestinal enzymes or reduce spasms
- Vitamin or mineral supplements, such as B12 and iron
- Medium-chain triglycerides as fat substitutes, because they do not require micelle formation for absorption and their route of transport is through blood vessels rather than lymphatic vessels
In severe intestinal disease, such as extensive regional enteritis and following a massive resection, intravenous nutrition may become necessary.[11]
Treating the underlying cause
Some malabsorption diseases have specific treatments:[3][10]
- A gluten-free diet helps treat celiac disease
- A lactose-free diet helps correct lactose intolerance
- Supplementing the first bite of milk-containing food products with products like Lactaid can help with lactose intolerance
- The use of protease and lipase supplements is the therapy for pancreatic insufficiency
- Antibiotics are used to treat small intestinal bacterial overgrowth, tropical sprue, and Whipple disease
- Corticosteroids, anti-inflammatory agents such as mesalamine, and other therapies are used to treat regional enteritis