Malabsorption is a disorder in which sufferers struggle to digest foods or absorb their nutrients. This condition occurs in many different diseases. It can cause sufferers to become generally malnourished or deficient in essential nutrients.
For the body to function, it needs nutrients that allow it to maintain and repair itself. Nutrients are also used to produce energy and fight off infections. There are many essential vitamins and minerals that people derive from their diet.
When we eat food, it goes through three stages of digestion.
The fats, proteins, and complex sugars that we eat are broken down by the acids in our stomach, bile from our livers, and enzymes from our pancreas. When these nutrients are broken down, micronutrients are released.
The cells around our small intestines absorb most of the nutrients we eat.
From there, these nutrients travel throughout the body, where they used or stored for later.
If this process is halted in any way, malabsorption can occur. The seriousness of this issue and the symptoms that it causes can vary based on several factors. Is the disorder inhibiting the body’s ability to digest food? Which nutrients is the body struggling to digest?
Digestive Issues
Enzymes from the pancreas and bile are both required to correctly digest proteins, fats, and carbohydrates. If the liver or pancreas is diseased, it could inhibit the body’s ability to produce these substances. This can also occur in patients that suffer from cystic fibrosis. Enzymes from the pancreas may struggle to reach the body’s digestive tract.
Issues With Absorption
When the intestines cannot properly absorb nutrients, these nutrients are expelled from the body through bowel movements. This may occur when the tissue or cells of the intestine has been damaged in some way. This can also happen when the intestine has been shortened it some way, which could happen after surgery. This reduces the intestine surface area, which means there is less time for the body to absorb nutrients from food as it moves throughout the digestive tract.
For the body to absorb vitamin B12, it needs acid from the stomach as well as a substance called intrinsic factor, which is made by the stomach’s parietal cells. Acid from the stomach causes B12 to separate from proteins, which allows the intrinsic factor and the B12 to bind. If either stomach acids or intrinsic factor is not present, B12 cannot be absorbed by the intestines, which can cause a deficiency in vitamin B12. This may occur as people grow older. Several medications can cause less stomach acid to be produced. This issue may also occur after gastric bypass surgery if someone has a disorder that has caused damage to their parietal cells, or in patients that are suffering from general malabsorption.
Issues With Transport
After nutrients have been absorbed, they are transported through the body by cells. In some cases, transport problems may occur. This may happen in patients that are experiencing issues with their lymphatic system, which can be caused by lymphoma or abetalipoproteinemia, which is a rare hereditary disorder.
Malabsorption And Its Causes
Many disorders and diseases that can lead to malabsorption. These are just a few examples:
- Cancers, such as stomach cancer, pancreatic cancer, or lymphoma
- Conditions that cause the bile ducts to close, narrow, or disappear like biliary atresia, or block bile flow, like cholestasis, which leaves the body with insufficient bile for digestion
- Celiac disease, a type of autoimmune disease that causes the lining of the intestines to be damaged
- Intestinal damage, like the damage that can occur during radiation treatment
- Cystic fibrosis, a hereditary disorder that can impact the pancreas and make it more difficult for enzymes from the pancreas to be transported through the body
- A decrease in the production of intrinsic factor
- Disorders that make it more difficult for the body to circulate throughout the body, like heart disease
- Enzyme deficiencies, or intolerances to foods, like lactose intolerance
- Hyperthyroidism
- AIDS
- Digestive tract infections, such as parasitic, bacterial, and viral infections
- Inflammatory bowel diseases, such as ulcerative colitis or Crohn’s disease
- Medications that inhibit the production of stomach acid, like phenytoin
- Liver disease
- Pancreatic disease or insufficiency, which can cause the amounts of enzymes the pancreas produces to be decreased
- Certain types of surgeries, like gastric bypass or bowel resection s
- Scleroderma
- Zollinger-Ellison syndrome, a rare disorder that causes tumors to develop on the intestines or pancreas
Symptoms Of Malabsorption
The symptoms of a patient with malabsorption can vary based on the root cause of their condition. The type of nutrient someone is deficient in and the extent of the deficiency. The signs may be severe immediately, or they may gradually get worse in time. The body stores certain nutrients, like vitamin B12. Because of this, symptoms of deficiency will only become apparent after stores have been depleted. This is also true of pancreatic enzyme deficiency. Symptoms may not show until approximately 90% of the production capacity in the body has been halted.
A few of the symptoms that are most associated with general malabsorption are:
- Chronic diarrhea
- Steatorrhea, which causes bulky and oily stools with a strong odor
- Children may be diagnosed with failure to thrive.
- Cramps, gas, bloating, and general abdominal pain.
Many symptoms may be caused by nutritional deficiencies or by poor health. Some of these symptoms are:
- Fatigue
- Ascites, which causes a build-up of fluid in the abdomen
- Rashes or dry and scaly skin
- Glossitis, which is inflammation of the tongue
- Unexplained weight loss or decrease in muscle mass
- Nausea
- Accumulation of fluid in the feet, legs, and hands
- Mouth inflammation
- Gum disease
- Paleness
- Tingling or a number feeling in the hands or feet.
- Pain in the muscles or bones
- Issues that can occur when someone suffers from chronic malabsorption, include:
- Iron deficiency (anemia)
- Confusion or difficulty concentrate
- Failure to grow or develop in children
- Osteoporosis
- Malnutrition
- Deficiencies in key vitamins, like vitamins D, K, and A
Testing For Malabsorption
Testing is primarily done to:
Evaluate patients that may be at a higher risk for malabsorption on account of a condition they suffer from, like cystic fibrosis
Diagnose malabsorption, find the root causes, and determine the type and extent of nutritional deficiencies
Diagnose possible complications, like anemia
Determine how effective malabsorption treatment has been
While there are many tests that a doctor might order if they suspect malabsorption, there isn’t any single test that can provide a diagnosis. In most cases, when a professional is ordering tests, they will look at additional factors as well, such as medical and family history, symptoms, and the results of a general examination. In many cases, testing will be done in stages so that other possible causes can be ruled out before a doctor provides a diagnosis. Examples of tests that may be run include:
Typically, the first set of tests will look at the condition of cells, organs, and the digestive system. From there, healthcare providers will search for a cause for primary symptoms, such as chronic diarrhea, which is one of the most common malabsorption symptoms.
After that, follow-up tests may be ordered to find or rule out any diseases that are linked with malabsorption. Tests can also find deficiencies and potential complications.
Lab Tests
Common initial tests are:
Complete blood count: Evaluates red blood cells and checks for anemia, which can be caused by B12, folate, or iron deficiency.
Comprehensive metabolic panel: Detects electrolyte imbalances, evaluates proteins, and function of various organs, like the liver.
Prealbumin: Checks for protein malabsorption and can provide information about general nutritional deficiency
Erythrocyte sedimentation rate: Detects bodily inflammation, which can be caused by conditions like inflammatory bowel disease
Fecal fat testing: To see if the body is properly digesting fat
Stool culture: Used to check for bacterial infection
Diff toxin and Clostridium difficile testing: Checks for bacterial overgrowth, which can cause chronic diarrhea
Ova and parasite examination: Checks for parasites, which can cause chronic diarrhea
White blood cells in stool: Can be found in patients suffering from certain inflammatory intestinal conditions
Gastrointestinal pathogen testing: Looks for bacteria, parasites, and viruses in the stool, which can cause both diarrhea and infections of the digestive tract
Thyroid-stimulating hormone: Identifies or eliminated thyroid disease
After the initial round of tests, healthcare practitioners will look at those results as well as the information from examinations and order additional tests. Examples of tests that may be ordered include:
Fecal occult blood test: Looks for digestive tract bleeding
Testing for deficiency in vitamins like A, B12, and D
Prothrombin time: Tests for deficiency in vitamin K
Celiac disease testing
Celiac disease testing, such as trypsinogen, CF gene mutation panels, and sweat tests
Tests that evaluate the pancreatic function, like stool trypsin, fecal elastase, and blood tests
Other tests that may be ordered are:
Hydrogen breath test: Can identify digestive system bacterial overgrowth and lactose intolerance
Methylmalonic Acid: Can detect vitamin B12 deficiency before signs are shown
Xylose absorption test: Carbohydrate digestive testing
Lactose tolerance test: This test, which can be used when testing for lactose intolerance, can also be used when diagnosis malabsorption
