Malabsorption is a disorder that occurs when people are unable to absorb nutrients from their diets, such as carbohydrates, fats, minerals, proteins, or vitamins.

Some commonly known disorders related to malabsorption are lactose intolerance and celiac disease. People with a history of bowel or stomach surgery may also have malabsorption disorders.

Because malabsorption affects a person’s abilities to get nutrients from food, it is essential that they see a doctor to get a diagnosis and treatment as quickly as possible.

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Problems with the digestive process may cause malabsorption.

Malabsorption is the result of a disruption in at least one part of a person’s digestion.

Digestion begins when the enzymes in a person’s saliva start to break down food into smaller parts that the body can absorb.

Enzymes continue to break down the food as it travels through the esophagus, stomach, and large and small intestines before it leaves the body as waste products.

Malabsorption can occur if someone does not have enough digestive enzymes, bacteria or other foreign invaders are present, or movement in the small or large intestine is faster than usual.

There are many different malabsorption disorders, each having a different underlying cause. Doctors usually classify malabsorption disorder types by the symptoms they cause.

According to the Semmelweis University School of Medicine, these categories include:

Cardiovascular disorders

  • congestive heart failure
  • constrictive pericarditis
  • mesenteric vascular insufficiency

Drug-induced disorders

Taking the following medications can lead to malabsorption disorders:

  • cholestyramine
  • colchicine
  • irritant laxatives
  • neomycin
  • phenindione

Impaired digestion

  • gastric surgery, such as gastric bypass or weight-loss surgery
  • gastrinoma

Inadequate absorptive surface

  • jejunoileal bypass
  • short bowel syndrome


  • acute infectious enteritis
  • parasitic infections, such as giardia, or helminthiasis
  • tropical sprue
  • Whipple’s disease

Intestinal mucosa abnormalities

Lymphatic obstruction

Reduced bile salt concentration

  • bacterial overgrowth from the small intestine
  • ileal resection or disease
  • liver disease

Some types of malabsorption syndromes do not fall under any category. These include conditions, such as diabetes mellitus, carcinoid syndrome, and mastocytosis.

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Gas and diarrhea are potential symptoms of malabsorption.

Malabsorption symptoms vary according to the cause, the severity of the condition, and how long a person has had the disorder.

Examples of some immediate malabsorption symptoms that may occur:

  • bloating and stomach distention
  • diarrhea
  • fatigue
  • gas
  • steatorrhea, or stool that is pale to white
  • stools that appear “greasy” in texture
  • stomach cramping
  • weakness

People need nutrients from food to maintain a healthy body. When their body cannot properly absorb these nutrients, they might experience the more long-term effects of malabsorption.

These include:

  • bone pain
  • bones that fracture easily
  • iron-deficiency anemia, which can result in shortness of breath
  • muscle wasting
  • a sore tongue
  • weight loss

While everyone may experience some bloating, nausea, and even diarrhea from time to time, anyone who experiences a continued pattern of stomach upset should see their doctor.

People should seek immediate medical attention if they observe blood in their stool (sometimes this blood may look like dried coffee grounds) or are coughing up blood.

Signs people should make an appointment with their doctor include:

  • continued abdominal bloating
  • fatigue
  • frequent diarrhea
  • sore tongue
  • weakness
  • weight loss

A doctor can help evaluate a person’s symptoms and start to make a diagnosis.

To make a diagnosis of a malabsorption disorder, a doctor will ask a person about their symptoms.

They might ask about when a person first noticed the symptoms, what makes these symptoms worse or better, and what types of medical conditions a person already has.

Based on this, a doctor may recommend a variety of tests to rule out or confirm a diagnosis.

Tests include:

  • Blood tests: Doctors may request full blood counts, as well as electrolyte balances. Checking protein levels in the blood may also help a doctor understand whether someone is malnourished and to what degree.
  • Stool tests: A doctor may request a stool sample to test for the presence of excess fat in the stool. High levels of fat might mean that a person is not absorbing the fat their diet very well.
  • Breath tests: A doctor commonly performs a breath test to check for the presence of hydrogen gas in those who may be lactose intolerant. The intestines will produce excess hydrogen gas if they cannot absorb lactose correctly.
  • Imaging tests: Sometimes, a doctor may order imaging studies to check the function and structure of the digestive organs.

A doctor may also recommend an esophagogastroduodenoscopy (upper GI scope) or a colonoscopy (lower GI scope) to examine the intestinal lining and take tissue biopsies to diagnose certain conditions.

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A nutritionist can create a diet plan for someone with malabsorption.

Treatment options depend upon the underlying cause.

For example, doctors will treat malabsorption caused by lactose intolerance in a different way to malabsorption due to liver disease.

Initially, a doctor may recommend that a person avoids the food type that is causing the malabsorption, such as lactose or gluten-containing foods.

The doctor can evaluate the nutrients present in this food type and make recommendations on supplementation as a means of enhancing nutritional intake.

A doctor may also make recommendations for replacing missing enzymes or prescribing medications to enhance appetite. People may also choose to meet with a registered dietitian to establish a diet that is nutritious, but less likely to cause unpleasant symptoms associated with malabsorption.

A doctor will likely recommend frequent follow-up appointments to assess the effectiveness of the treatment and make new recommendations if necessary.

The complications associated with malabsorption depend upon the severity of the underlying condition.

Malabsorption can lead to weight loss, malnutrition, and even failure to thrive in many people.

A person can also experience impaired wound healing, a deficient immune system, and low energy levels.

Malabsorption syndromes can have a dramatic effect on a person’s life.

Anyone who notices their symptoms become more frequent and less occasional should see a doctor as soon as possible. This way, they can receive treatment before they experience significant unwanted weight loss and other side effects.