Malabsorption syndrome is an alteration in the ability of the intestine to absorb nutrients adequately into the bloodstream. Malabsorption may be due to an abnormality of the gut wall, failure to produce enzymes or bile to aid digestion, or there may be abnormalities of the flora of the gut. Malabsorption may occur for many nutrients or for specific carbohydrates, fats or micronutrients. Protein, fats, and carbohydrates normally are absorbed in the small intestine — the small bowel also absorbs about 80 percent of the eight to ten liters of fluid ingested daily.
Many different conditions affect fluid and nutrient absorption by the intestine. A fault in the digestive process may result from failure of the body to produce the enzymes needed to digest certain foods. Congenital structural defects or diseases of the pancreas, gall bladder, or liver may alter the digestive process. Inflammation, infection, injury or surgical removal of portions of the intestine may inhibit absorption abilities. Reduced length or surface area of intestine available for fluid and nutrient absorption can also result in malabsorption.
Radiation therapy may injure the mucosal lining of the intestine, resulting in diarrhea that may not become evident until several years later. Furthermore, the use of some antibiotics can also affect the bacteria that normally live in the intestine, thus affecting intestinal function.
Common disorders that can lead to malabsorption syndrome include cystic fibrosis, chronic pancreatitis, celiac disease or gluten enteropathy, short bowel syndrome, intestinal lymphangiectasia, Whipple’s disease, inflammatory bowel disease and irritable bowel syndrome.
Malabsorption causes weight loss, glossitis, carpopedal spasms, absent tendon reflexes, cutaneous bruising, flatulence and abdominal distention, bloating or discomfort resulting from increased intestinal bulk and gas production.
The most common symptoms of malabsorption include:
- anemia, with weakness and fatigue due to inadequate absorption of vitamin B-12, iron, and folic acid
- diarrhea, steatorrhea (excessive amount of 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. The individual may also report explosive diarrhea with greasy, foul-smelling stools
- edema from decreased protein absorption
- malnutrition and weight loss due to decreased fat, carbohydrate, and protein absorption
- muscle cramping from decreased vitamin D, calcium, and potassium levels
- 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. Blood clotting disorders may occur due to a vitamin K deficiency.
Secondary nutritional deficiencies develop in proportion to the severity of the primary disease and the area of the GI tract involved. Many patients with malabsorption are anemic, usually because of deficiencies of iron (microcytic anemia) and folic acid (megaloblastic anemia) but also from the B vitamins, calcium, vitamin D, vitamin K (mainly fat-soluble), and niacin.
Protein malabsorption may lead to hypoproteinemic edema, usually of the lower limbs, and secondary endocrine deficiencies may result from malnutrition due to the high risk of polyunsaturated fatty acid (PUFA) deficiency. Moreover, patients with malabsorption will become immunosuppressed due to the nutritional deficiencies.
Fluid and nutrient monitoring and replacement is essential for any individual with malabsorption syndrome. Hospital-ization may be required to treat severe fluid and electrolyte imbalances. Consultation with a dietitian to assist with nutritional support and meal planning is helpful. If the patient is able to eat, the diet and supplements should provide bulk and be rich in carbohydrates, proteins, fats, minerals, and vitamins. It is often recommended that those suffering from malabsorption syndrome eat foods as close to already digested form as possible, and eat several small, frequent meals throughout the day, avoiding fluids and foods that promote diarrhea. Intake and output should be monitored, along with the number, color, and consistency of stools.
Vitamin and mineral supplements are advised. Other helpful supplements may include probiotics and prebiotics.
“There is no doubt that a healthy digestive system is critical for proper nutrient absorption,” says Tim Gamble, vice president of sales and marketing for Nutraceutix, Inc. “A healthy gut to some extent means that there is a healthy, naturally occurring population of probiotic bacteria present in the intestines. Research indicates that viable, properly delivered probiotics can play a key role in strengthening the function of the intestines from digestion of food to prohibiting pathogenic bacterial growth to immune system stimulation. If one is hoping to gain weight by manipulating or supplementing one’s diet, perhaps beyond that which is considered normal or routine, a healthy gut is critical to allowing one to do so without digestive discomfort or dysfunction. Probiotic supplementation is probably a wise choice before and during a weight gain regimen.”
Medical management for malabsorption syndrome is dependent upon the cause. (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). Management of some individuals may require injections of vitamin B-12 and oral iron supplements. The doctor may also prescribe enzymes to replace missing intestinal enzymes, or antispasmodics to reduce abdominal cramping and associated diarrhea. People with cystic fibrosis and chronic pancreatitis require pancreatic supplements. Those with lactose intolerance or gluten enteropathy will have to modify their diets to avoid foods that they cannot properly digest.