Malabsorption is one specific symptom characterized by difficulties in the digestion or absorption of nutrients from food substances.
It is also a main symptom of a larger entity called the malabsorption syndrome! Therefore, malabsorption syndrome is an alteration in the ability of the intestine to absorb nutrients adequately into the bloodstream. Several researches done in the past have shown that this condition can be caused by a variety of diseases or conditions, including cystic fibrosis, lactose intolerance and several others…
Pathophysiology of the condition
It is necessary to point out that- in order to better understand the mechanisms of malabsorption, understanding the normal physiological process of digestion and absorption by the intestinal tract is necessary. The fact is that the digestion and absorption can be divided into 3 major phases:
- The luminal phase is the phase in which dietary fats, proteins, and carbohydrates are digesteded by secreted digestive enzymes and bile which is also secreted into the lumen
- The mucosal phase is based on the integrity of the membrane of intestinal epithelial cells which purpose is to transport digested products from the lumen into the cells
- The postabsorptive phase is phase characterized by transport of reassembled lipids and other extremely important nutrients through lymphatics and blood circulation
Causes and symptoms of malabsorption
Here are some basic facts about digestion and absorption. Normally- proteins, fats, and carbohydrates are absorbed in the small intestine. Experts are saying that the small bowel also absorbs about 80% of the 8 to 10 liters of fluid ingested daily. Important thing to know is that there are many different conditions that affect fluid and nutrient absorption by the intestine. Some conditions are related to some failure of the body to produce the enzymes needed to digest certain foods and sometimes- it is all because of some congenital structural defects or diseases of the pancreas, gall bladder, or liver may alter the digestive process.
It is also logical to assume that every inflammation, infection, injury, or surgical removal of portions of the intestine may also result in absorption problems. Surgeons are also saying that common condition that could contribute to malabsorption is reduced length or surface area of intestine available for fluid. It is also proven that every radiation therapy may injure the mucosa layer if the intestine, resulting in diarrhea. Some drugs (antibiotics) can also affect the bacteria that normally live in the intestine and affect absorption! Several disorders can lead to malabsorption syndrome, including cystic fibrosis, chronic pancreatitis, lactose intolerance, and gluten enteropathy (non-tropical sprue.) pernicious anemia, tropical sprue, Whipple's disease
Bassen-Kornzweig syndrome, biliary atresia, celiac disease, intestinal parasites, Shwachman-Diamond syndrome and many others!
Researches showed that risk factors for malabsorption syndrome include:
- Traveling to foreign countries
- Intestinal surgery of any kind
- Family history of malabsorption or cystic fibrosis
- Use of certain drugs, such as mineral oil or other laxatives
- Excess alcohol consumption.
Symptoms of malabsorption
The most common symptoms of malabsorption include:
- Edema (fluid retention in the body's tissues) because of decreased protein absorption
- Malnutrition and weight loss due to decreased fat, carbohydrate, and protein absorption.
- Muscle cramping due to decreased vitamin D, calcium, and potassium levels
- Anemia, with weakness and fatigue due to inadequate absorption of vitamin B12, iron, and folic acid
- Diarrhea, steatorrhea-fat in the stool and abdominal distention with cramps, bloating, and gas due to impaired water and carbohydrate absorption, and irritation from unabsorbed fatty acids.
- Muscle wasting and atrophy due to decreased protein absorption and metabolism
- Perianal skin burning, itching, or soreness due to frequent loose stools.
- Irregular heart rhythms may also result from inadequate levels of potassium and other electrolytes.
Diagnosis of malabsorption
It is extremely important that diagnosis of malabsorption could be extremely difficult and that the identification of the underlying cause usually requires extensive diagnostic testing.
- medical history and physical examination
Every patient should know that the first diagnostic phase should be a thorough medical history and physical examination by a physician.
- Stool analysis and biopsy
In almost every case of malnutrition, a 72-hour stool collection should be ordered for fecal fat measurement; increased fecal fat in the stool collected indicates malabsorption. Sometimes, when these methods are insufficient, a biopsy of the small intestine may be done in order to help making a difference between malabsorption syndrome and small bowel disease.
- Ultrasound, CT and MRI
Ultrasound, computed tomography scan (CT scan), magnetic resonance imaging (MRI), barium enema, or other x rays to identify abnormalities of the gastrointestinal tract and pancreas.
Laboratory studies of the blood may include:
- Serum vitamin A and carotene. These should be low due to bile salt deficiency and impaired fat absorption.
- D-xylose test. Of course, decreased excretion may indicate malabsorption.
- Serum cholesterol. Cholesterol should be low due to decreased fat absorption and digestion.
- Serum sodium, potassium, and chloride. They should also be low due to electrolyte losses with diarrhea.
- Serum calcium. May be low due to vitamin D and amino acid malabsorption.
- Schilling test. May indicate malabsorption of vitamin B12.
Consequences of Malabsorption
It is extremely important to point out that, while malabsorption is a serious problem in all people, it is especially serious in newborn babies, infants and children. How come? Well, everyone knows that babies, infants and children are still developing, and adequate nutrition is vital to proper growth and development. What happens in malabsorption? Well, because of malabsorption and consequently malnutrition, growth will not occur at the regular tempo. That’s why-the fact is that permanent disabilities related to growth and development may result. Also, two common complications are anemia and osteoporosis.
Fluid and nutrient monitoring and replacement
Every patient should be aware of the fact that fluid and nutrient monitoring and replacement is probably the most important therapy procedure for any individual with malabsorption syndrome. Of course, in some serious cases-even hospitalization may be required. Patient should not do anything alone but consulting with a dietitian. Beside all this, experts are saying that also supplements should be provided in order to supplement depleted carbohydrates, proteins, fats, minerals, and vitamins.
Vital body signs and malabsorption monitoring
Experts are saying that all the patients with malabsorption syndrome should be monitored for dehydration. What are the signs of dehydration? Well, the most common are:
- dry tongue
- mouth and skin
- increased thirst
- low, concentrated urine output
- feeling weak or dizzy when standing
Not only that- all other vital signs such as pulse and blood pressure should be monitored, observing for increased or irregular pulse rate, or low blood pressure.
Other specific medical management
It is also logical to assume that the type of treatment will also depend on the type of underlying condition that caused the malabsorption! It is important to point out that the treatment for tropical sprue consists of folic acid supplements and long-term antibiotics. Whipple's disease also may require long-term use of antibiotics, such as tetracycline. If the cause of malabsorption is lack of some enzymes, then in that case- the doctor may also prescribe enzymes to replace missing intestinal enzymes, or antispasmodics to reduce abdominal cramping and associated diarrhea.
Corticosteroids and other anti-inflammatory agents help treat regional enteritis. Similarly, a lactose-free diet helps correct lactose intolerance; supplementing the first bite of milk-containing food products with Lactaid also helps. If there is case of folate deficiency and possibly B12 deficiency too it is possible to give an injection of vitamin B12 before starting folate supplementation.
Every patient should know that there are no therapy guarantees because the expected course for the individual with malabsorption syndrome varies depending on the cause. Big problem is that the onset of symptoms may be slow and difficult to diagnose, and that’s why- treatment is often late! Beside all this- the fact is also that treatment may be long, complicated, and changed often for optimal effectiveness.