~ by Jo Jordan
Malabsorption – the failure to completely absorb nutrients from the gastrointestinal tract – is an enormous health care problem in the United States today. The list of causes, signs, symptoms, clinical features, and complications of malabsorption is so long, it’s practically mind-boggling. The causes alone total over two hundred!
Many serious illnesses are linked to malabsorption, celiac disease for example. The prevalence of celiac disease alone – the most common inherited malabsorption syndrome – is approximately one percent1 of the general population of the United States, and the numbers have been increasing over time.
But what, exactly, is malabsorption, and what – if anything – can be done to protect yourself from this syndrome?
How Malabsorption Works Against Good Digestive Health
Rather than being one specific disorder, malabsorption is a syndrome that includes a number of conditions whereby food nutrients are not adequately absorbed in the small intestine. To prevent and/or alleviate the symptoms and resulting complications of malabsorption, it’s important to understand what happens (or does not happen) when this condition sets in.
In a person with a healthy digestive system, food is eaten and digested, and nutrients are absorbed into the bloodstream in the small intestine. If a disorder disrupts the digestion of food, or directly interferes with nutrient absorption, malabsorption becomes a potential factor.
Various substances are necessary for healthy digestion to take place. Conditions that prevent sufficient mixing of food with substances such as digestive enzymes and hydrochloric acid (HCl) in the stomach can seriously affect digestion. This can happen to patients who’ve had a part of their stomach surgically removed.
For people with other types of disorders, adequate amounts or types of digestive enzymes don’t get produced. Insufficient bile production, an abundance of HCl, or too much bad bacteria growing in the small intestine may also negatively effect digestion.
Types of Malabsorption
While malabsorption can involve a general inability to absorb food, it is predominantly the inability to absorb certain sugars, fats, proteins, or vitamins from food.
There are three basic categories of malabsorption:
1. Selective, as with lactose malabsorption
2. Partial, as observed in those with abetalipoproteinemia (an inherited disorder that affects the absorption of dietary fats, cholesterol, and fat-soluble vitamins)
3. Total, as in the case of those with celiac disease
Within these categories, there are many specific types:
Sugar malabsorption, usually of lactose or milk sugar, is the most common form of malabsorption.
Fat malabsorption, a more serious health concern than sugar malabsorption, necessitates an evaluation of the bile ducts, pancreas, and small intestine.
Nutrient malabsorption: several distinct malabsorption conditions affect the various steps in the transportation of nutrients. For example, iron deficiency anemia – resulting from iron malabsorption by the small intestine – is often caused by celiac disease.
What Causes Malabsorption?
Nutrient absorption can be caused by disorders that have injured the lining of the small intestine. Comprised of villi and microvilli (tiny and even smaller finger-like projections of membrane), healthy intestinal lining provides a large surface area for absorption.
Surgical removal of part of the small intestine (intestinal resection) reduces the surface area for absorption (short bowel syndrome). Acute, abnormal intestinal lining resulting from bacterial, parasitic, or viral infections; alcohol and certain drugs (antibiotics); and chronically abnormal intestinal lining resulting from injurious diseases such as celiac and Crohn’s. Disorders that affect the remaining layers of the intestinal wall also inhibit absorption.
The two hundred causes can be classified into four distinct categories:
1. Those relating to the mucous membranes (mucosal) such as cow’s milk intolerance
2. Intraluminal, that is, causes relating to the cavity of the intestine such as chronic pancreatitis
3. Structural, for example Crohn’s disease
4. Causes outside the gut such as diabetes and eating disorders
Here is a list of some of the causes of malabsorption, by category:
- AIDS (Aquired Immune Deficiency Syndrome)
- Celiac disease
- Cow’s milk protein intolerance
- Giardia lamblia / giardiasis
- Intestinal tuberculosis
- Intestinal lymphectasia (and other causes of lymphatic obstruction include lymphoma, tuberculosis and cardiac disease)
- Soy milk protein intolerance
- Threadworm / roundworm
- Traveler’s diarrhea
- Tropical sprue (an nutrient absorption condition common in the tropics and subtropics)
- Whipple disease
Causes outside the gut
- Addison’s disease
- Carcinoid syndrome (a group of symptoms associated with tumors of the appendix, bronchial tubes in the lungs, colon, and small intestine)
- Eating disorders
- Widespread skin disease
- Amyloidosis (a group of diseases in which a protein builds up in the organs and tissues)
- Certain surgery types (gastrectomy, surgical treatments for obesity, etc.)
- Crohn’s disease
- Diverticulae and strictures
- Eosinophilic gastroenteropathy (a rare childhood disease characterized by white blood cell inflammation of the intestine)
- Fistulae (inadequate gastric mixing results)
- Mesenteric arterial insufficiency
- Radiation treatment damage
- Short bowel syndrome
- Chronic pancreatitis
- Cystic fibrosis
- Defective bile salt secretion
- Zollinger-Ellison syndrome
- Abetalipoproteinemia (an inherited disorder that affects the absorption of dietary fats, cholesterol, and fat-soluble vitamins)
- Biliary atresia (a rare condition in newborns whereby the common bile duct between the liver and small intestine is blocked or absent)
- Certain medications (some antacids, some antibiotics, some medications used to treat obesity)
- Certain cancer types (lymphoma, pancreatic cancer, gastrinomas)
- Cholestasis (a condition whereby bile cannot flow from the liver to the duodenum)
- Chronic liver disease / PSC
- Collagen diseases
- Impaired enzyme transport
- Lactose intolerance (inability to digest the sugar lactose)
- Shwachman-Diamond syndrome (a genetic disease affecting the pancreas and bone marrow)
- Vitamin B12 malabsorption (may be due to juvenile pernicious anemia or tapeworm)
Symptoms of Malabsorption
Malabsorption signs and symptoms vary depending on the specific deficiency. Poor protein absorption, for example, can present with bodily swelling, dry skin, and hair loss, while insufficient absorption of specific sugars can result in abdominal bloating, explosive diarrhea, and severe flatulence. Inadequate absorption of fats in the digestive tract can result in stool that is bulky, pale, soft, and foul smelling (a condition known as steatorrhea).
Signs of malabsorption may include one or more of the following:
- Abdominal pain
- Bulky stools
- Changes in weight and growth
- Children may experience a failure to thrive
- Fatty stools
- Folate deficiency
- Iron deficiency anemia
- Muscle wasting
- Non-anemic iron deficiency
- Oily stools
- Skin changes
- Steatorrhoea (greasy, pale, bulky, and offensive-smelling stools)
- Undigested food in stools
- Vitamin B12 deficiency
Malabsorption can also affect growth and development, and/or lead to certain illnesses.
Numerous health concerns are directly or indirectly linked to malabsorption issues: low stomach acid; Candida albicans; gastroparesis; gluten intolerance; indigestion; and irritable bowel syndrome (IBS).
Long-term malabsorption can result in,
- Heart failure
- Kidney stones
- Osteoporosis and osteomalacia (bone disease)
Further malabsorption complications include infertility, rickets, and stunted growth in children. In addition, untreated celiac disease can lead to small bowel glandular tissue cancer or lymphoma.
When a patient is suffering with chronic diarrhea, nutritional deficiencies, and substantial weight loss despite a healthy diet, their health care provider may suspect malabsorption. More difficult to diagnose in older people than in the young, a variety of diagnostics are available to help make a determination.
Along with a complete physical exam, various other tests may be necessary to make an accurate malabsorption diagnosis:
A complete blood count (CBC) can determine whether or not anemia is the cause for malabsorption. Plasma viscosity (the thickness of the fluid in which blood cells are suspended), vitamin B12 level, red cell folate (folic acid), iron status, and clotting screen for vitamin K deficiency are measured. In addition, specific antibody screens can detect celiac disease.
Serum electrolytes can determine whether or not electrolyte imbalances – such as low levels of calcium, potassium, or magnesium – are the cause for malabsorption.
Liver function tests are performed to detect, evaluate, and monitor liver disease or damage.
Pancreatic function tests (blood tests) measure the gland’s ability to secrete an adequate supply of enzymes or other substances necessary for digestion. Amylase (the pancreatic enzyme responsible for digesting carbohydrates), lipase (the enzyme that digests fats), and trypsin (which digests proteins) levels are measured to determine pancreatic sufficiency.
Stool studies, the collection of stool samples over a two- or three-day period, is one of the most dependable ways to make a fat malabsorption diagnosis. More than seven grams of fat per day in the stool is a distinguishing malabsorption feature2. If parasites or their eggs are detected, a parasitic infection may be the cause of malabsorption.
A comprehensive, non-invasive home stool test is also available3. It provides data on digestive and pancreatic function, gut microbial ecology (bacteria and yeast), and parasitic presence.
Breath hydrogen tests (BHT) examine samples of expired air for bacterial overgrowth by measuring exhaled hydrogen and/or methane.
D-xylose absorption tests measure how well the intestines absorb simple sugar (D-xylose).
Secretin stimulation tests examine the pancreas’s ability to respond to the hormone secretin, produced by the small intestine when partially digested food has moved from the stomach to the area of the pancreas.
Other lab tests measure the malabsorption of specific substances such as lactose.
X-rays with barium liquid contrast require a chalky solution, barium, to be drunk to coat the lining of the small intestine. Barium appears white on X-ray film, revealing any structural abnormalities.
Computerized tomography scans (CT or CAT) is a specialized X-ray technique capable of collecting more detail than a standard X-ray. CT scans can determine whether or not there is an underlying illness such as chronic pancreatitis or Whipple disease for which malabsorption has become a symptom and/or complication.
Endoscopic retrograde cholangiopancreatography (ERCP) combines the use of X-rays and an endoscope to examine the liver’s bile ducts and pancreatic duct (biliary tree assessment). Under sedation, a small tube is inserted down the throat into the duodenum. A dye is injected into the duct, and an X-ray is taken.
Endoscopic tests for specific sections of the gastrointestinal (GI) tract are sometimes used to do a visual exam and assist with malabsorption diagnoses. All use a thin, flexible tube with a lighted camera inside the tip, and a small clipper (for biopsies), enabling health care providers to examine the GI tract lining.
A biopsy – the taking of a tissue sample from the intestinal lining to be used for further examination – may be required to detect abnormalities in the small intestine’s lining. The tissue is removed via the endoscope’s clipper.
Since many malabsorption syndromes are hereditary, genetic screening may help prevent passing on the syndrome to unborn children. Early detection for infants and children is one of the best preventatives for hereditary malabsorption.
For some people, prevention of malabsorption syndromes can be as simple as avoiding foods or other substances (such as impure/unfiltered water sources while traveling or certain medications) that produce gastrointestinal distress and/or an allergic reaction. Subsequent monitoring to prevent additional nutritional deficiency illnesses is indicated.
Sometimes, a specific food can cancel out the effectiveness of a prescribed medication, leading to serious health problems over the long-term. Understanding how to prevent malabsorption syndromes can be a crucial part of healthy living.
Learn about medication interactions as well as those between foods and other substances. Grapefruit juice reacts with various drugs causing potentially dangerous side effects. Lipitor (for lowering cholesterol) if taken with recently ingested grapefruit or its juice may result in muscle cramps. Examine prescription drug inserts, which sometime outline medications that do not mix well.
Observe urine for discoloration and/or an unusual scent, which may coincide with the ingestion of certain drugs. Be aware of the color and quality of feces, particularly if it seems to contain foreign matter. Providing a fecal sample to your health care provider can confirm the presence of parasites, which may lead to vitamin B12 malabsorption.
Note any changes in your overall health. For example, muscle cramps and bone pain may indicate a vitamin D deficiency.
Malabsorption Syndrome Treatment
Prognosis depends on the underlying condition that is causing malabsorption. But much can be achieved – such as alleviating symptoms and decreasing the likelihood of further illness – through lifestyle changes, probiotics, and vitamin and nutrient supplementation.
While there are over two hundred suspected causes of malabsorption and treatment varies from one syndrome to the next, a few basic treatment principles apply to nearly all malabsorption cases:
- Ask about prescription medications. Depending on the underlying condition – antibiotics for a bacterial infection or anti-inflammatories for conditions such as Crohn’s disease – drugs may be helpful.
- Avoid foods that seem difficult to digest.
- Be active in planning your diet to get at the root cause of malabsorption. For example, lactose or gluten intolerance is a common cause for malabsorption.
- Consider taking enzyme fortified drinks and supplements.
- Drink lots of water to help flush out the system, and assist in effective kidney function.
- Know what foods are more readily absorbed when eaten with certain others (food combining).
- Replace lost nutrients with alternate foods and high protein-vitamin supplements.
- Take a multi-vitamin. It simplifies the process of ensuring adequate daily intake of a variety of vitamins and nutrients.
- Take a probiotic. They may help increase the absorption of trace minerals, especially in people with high-phyate diets (i.e. legumes, nuts, and whole grains).
- Work with a specialist, providing stool samples etc., to determine the specific cause of malabsorption.
Many serious illnesses are linked to malabsorption. An inflamed ileum (such as with various types of Crohn’s disease) can interfere with the absorption of vitamin B12 and bile salts. Any inflammation along the length of the small intestine will seriously impair the absorption of all food.
Although malabsorption is a serious health care problem with an enormous array of causes and complications, a great deal can be achieved through simple lifestyle changes.
Prognosis greatly depends upon the underlying condition causing malabsorption, but the implementation of a prevention and treatment regimen including probiotics, and vitamin and nutrient supplementation can substantially alleviate symptoms, and prevent the onset of many more serious complications.