Malabsorption Definition:
Malabsorption is the inability to absorb nutrients through the gut lining into the bloodstream. Malabsorption is the failure of the GI tract to absorb one or more substances from the diet.
Malabsorption is a broad term used to describe the inability to absorb nutrients through the gut lining into the bloodstream. The impaired absorption by the intestines of nutrients from food. Malabsorption is not a disease by itself, but rather the result of some other condition that is present. The small intestine (also called the small bowel) is typically involved in malabsorption, since the majority of nutrients are absorbed there. Malabsorption may affect one or more of the many nutrients present in the diet, including protein, fat, carbohydrate, vitamins, and minerals.
Malabsorption means the failure of the GI tract, usually the small intestine, to absorb one or more substances from the diet. This is generally the result of some defect or damage to the mucosal lining of the small intestine where most of our nutrient absorption takes place. The most common symptoms of malabsorption syndrome are diarrhea, bloating, flatulence, cramping and weight loss. Over time, one may become deficient in iron, proteins, various vitamins and minerals and this can lead to degrees of malnutrition and a variety of anemias.
The most common anemias that may occur are vitamin B12, folate, and iron deficiency. Vitamin K malabsorption causes the blood to thin out and could result in excess bleeding. Protein depletion can lead to impaired bone formation and osteoporosis, and calcium deficiency leads to weakening and demineralization of the bone, causing a condition called osteomalacia. Impaired absorption of vitamin A could result in poor vision and night blindness as well as dermatitis. Malabsorption of protein, fat and carbohydrate leads to loss of calories, generalized malnutrition and diarrhea.
Normally, foods are digested and nutrients are absorbed into the bloodstream mainly in the small intestine. Malabsorption may occur if a disorder interferes with the digestion of food or if a disorder interferes directly with the absorption of nutrients. Digestion can be affected by disorders that prevent adequate mixing of food with digestive enzymes and acid from the stomach. Inadequate mixing may occur in a person who has had part of the stomach surgically removed. In some disorders, the body produces inadequate amounts or types of digestive enzymes, which are necessary for the breakdown of food. For example, a common cause of malabsorption is insufficient production of digestive enzymes by the pancreas, as occurs with some pancreatic diseases, or by the small intestine, as occurs in lactase deficiency. Decreased production of bile, too much acid in the stomach, or too many of the wrong kinds of bacteria growing in the small intestine may also interfere with digestion.
Symptoms of malabsorption are caused by the increased passage of unabsorbed nutrients through the digestive tract or by the nutritional deficiencies that result from inadequate absorption.
The inadequate absorption of fats in the digestive tract results in stool that is light-colored, soft, bulky, and unusually foul smelling (such stool is called steatorrhea). The stool may float or stick to the side of the toilet bowl and be difficult to flush away. The inadequate absorption of certain sugars can cuse explosive diarrhea, abdominal bloating, and flatulence.
Malabsorption can cause deficiencies of all nutrients or selective deficiencies of proteins, fats, sugars, vitamins, or minerals. People with malabsorption usually lose weight. The symptoms vary depending on the specific deficiencies. For example, a protein deficiency can cause swelling (edema) anywhere throughout the body, dry skin, and hair loss.
Specific malabsorption disorders include:
 Lactose intolerance is a common disorder caused by a lack of a specific enzyme necessary to break down a sugar in milk, resulting in diarrhea, cramps, and gas.
Celiac disease is a hereditary disorder involving an intolerance to gluten, a protein found in wheat and rye flours. Symptoms include a failure to grow and the passage of fatty, foul-smelling stools that float to the top of the toilet water. The disorder often can be diagnosed on the basis of symptoms and confirmed by examining a small sample of intestinal tissue. As the disease progresses, the fingerlike projections that line the intestinal walls, and from which nutrients are absorbed into the bloodstream, become flattened and smooth. Treatment involves consuming a gluten-free diet.
Tropical sprue is uncommon in the U.S. Symptoms include anemia and other nutritional deficiencies, weight loss, and diarrhea. A sore tongue and passage of fatty stools are common.
Whipple's disease is a relatively rare disorder, mostly affecting middle-aged men. Symptoms include severe malabsorption, nutritional deficiencies, chronic low-grade fever, diarrhea, and joint pain.
Other disorders - in addition to specific intestinal abnormalities or deficiencies, a number of other disorders can hinder absorption. Scleroderma, intestinal lymphoma, liver disease, pancreatic disease, and bacterial overgrowth are among the numerous conditions that can hinder absorption from the small intestine. Intestinal damage from radiation therapy or certain drugs also may affect absorption.
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