Syndrome of impaired intestinal absorption

The terms "intestinal suction syndrome", or "malabsorption syndrome", cover a wide range of conditions in which the assimilation of various nutrients is impaired.

Suction deficiency syndrome is the name of any disease in which important nutrients( one or more) or minerals are not digested or absorbed properly by the intestine. Fats are most often poorly digested, but sometimes proteins, carbohydrates, electrolytes( such as sodium and potassium), vitamins and minerals( iron and calcium) can also be poorly absorbed. Many diseases can lead to inadequate absorption;the prospect of the development of the disease depends on the success of the treatment of the underlying disease. Symptoms can fluctuate from the accumulation of gases, diarrhea and stomach cramps that occur only when certain foods are poorly digested( see "Lactose intolerance" for more information), to exhaustion and other signs of severe malnutrition.

Classification of

The violation of digestion and absorption of many food components at once is manifested by an increase in the size of the abdomen, discolored by liquid stench stool, muscle atrophy, especially proximal muscle groups, growth retardation and weight gain. At the same time, digestive disorders are distinguished in the lumen of the intestine or in the membrane of the brush border of enterocytes( maldigestia) and the disturbance of the transport of nutrients through the membrane of the brush border into the blood flow( actually malabsorption).

Deficiency of intestinal enzymes( disaccharidases, peptidases) causes a violation of the membrane digestion. When the enzymes of the pancreas are deficient, the cavitary phase of digestion suffers. Diseases of the liver and bile excretory system, accompanied by difficulty or complete cessation of bile flow into the intestine, intestinal dysbiosis lead to disruption of the cleavage and absorption of fats( biliary phase of digestion).In pathological conditions, especially in cases of atrophy of the mucous membrane of the small intestine, the structures responsible for the absorption processes( cellular phase) suffer to varying degrees. At the same time, the absorption of nutrients is also severely affected. In the case of pathology of intestinal lympho- and blood circulation, the further transport of absorbed substances worsens( the outflow phase).Violation of the endocrine function of cells of the intestinal wall leads to a change in the hormonal regulation of digestive-transport processes. Finally, the accelerated passage of food through the intestines helps to reduce the time of contact of the food lump with the suction surface, which further exacerbates the impairment of absorption.

The factors determining the digestive and absorption functions of the small intestine are localized in the cells of intestinal villi. Usually they appear there between the 10th and 22nd weeks of fetal development, and by the end of the second trimester of pregnancy the intestinal structure already resembles that of an adult. The most studied side of intrauterine development of the intestine is the formation of enzyme systems. Enzymes such as sucrose, maltase and isomaltase already at the earliest stages of fetal development are at a level comparable to the level of enzymes in the intestines of the mature organism. The activity of these enzymes remains unchanged throughout the entire intrauterine period, except for a brief increase in late pregnancy. The activity of lactase is found during the 12-14th weeks of the intrauterine period, the increase in the lactase content occupies the entire III trimester, and by the end of the intrauterine development the level of activity of this enzyme is 2-4 times higher than in the first year of life. Only a very small number of premature babies show clinical signs of intolerance to milk sugar - lactose. It should be noted that lactose intolerance is observed in approximately 20% of children under the age of 5 years., Classification of malabsorption syndrome The term "malabsorption syndrome" combines a large number of diseases and syndromes.

All cases of digestive disorders are divided into two groups.

group 1 - with a decrease in the concentration in the lumen of the small intestine of pancreatic enzymes.

2-nd group - with a decrease in the cavity concentration of bile acids.

Classification of secondary malabsorption syndrome identifies the following clinical forms:

1) gastric;

2) pancreatic;

3) hepatic;

4) intestinal.

However, this classification does not represent all types of secondary maldigestii, there are no primary disorders.

The classification of F. Brooks( 1974) is more advanced, according to which the general and selective( selective) maldigesties are distinguished. This classification does not take into account membrane digestion, it also does not divide the deficit of disaccharidases into congenital and acquired forms.

Numerous causative factors and development mechanisms underlying malabsorption syndrome are evidenced by the following classification.

1. Primary malabsorption syndrome( hereditarily caused) occurs when the function is impaired, the formation of insufficient or incorrect chemical structure of enzymes involved in the digestion of food components, as well as the violation of nutrient absorption in the intestine.

2. Secondary malabsorption syndrome( acquired): occurs with various diseases of the stomach( gastrogenic), pancreas( pancreatogenic), liver( hepatogenous), small intestine( enterogenic), and postoperative, endocrine, iatrogenic( with prolonged use of antibiotics, laxatives, cytostatics and other drugs, radiation therapy).

Causes of

• Any defect in the functioning of the digestive system( for example, inadequate production of bile acids by the liver or digestive enzymes by the pancreas or cells lining the intestine, or damage to the intestinal suction cells) can interfere with the normal digestion of food and the absorption of the right amounts of nutrients.

• The main cause of malnutrition is chronic pancreatitis( often associated with alcohol abuse), which can lead to a decrease in the production of pancreatic enzymes digesting food, especially fats and protein.

• Inflammation or other abnormality in the mucosa that lines the intestine may interfere with the absorption of nutrients through the intestinal wall. The operation to remove parts of the intestine can lead to an inadequate suction surface.

• This is called a syndrome of the small intestine.

• Infectious diseases( including acute infectious enteritis) and infection with tapeworms or other parasites can interfere with the digestion of food. Some infectious diseases can lead to the growth of intestinal bacteria, which can also cause insufficient absorption. AIDS patients are especially prone to insufficiency of absorption, as the disease damages the body's immune system and reduces its resistance to secondary infectious diseases that can cause digestive problems.

• Any blockage of the lymphatic system that can occur with lymphomas and tuberculosis, can also interfere with the absorption of food.

• Some cardiovascular diseases can lead to malnutrition.

Some drugs may stimulate insufficient absorption. These include cholestyramine( a drug that lowers cholesterol), neomycin( antibiotic), colchicine( a drug against gout) and some laxatives.

• Other diseases, including diabetes mellitus, hyper and hypothyroidism and carcinoid syndrome, can cause malnutrition for unknown reasons.

Symptoms of

• Diarrhea.

• Abundant, greasy and fetid stools.

• Excessive gassing.

• Discomfort or cramps in the stomach, especially after eating.

• Fatigue.

• Weight loss or exhaustion.

• Night blindness( insufficiency of absorption of vitamins).

• Easy bruising( insufficiency of absorption of vitamin K).

• Bone pain and painful muscle contractions( insufficiency of calcium absorption).

• Pallor and other signs of anemia.

Diagnosis

• Medical history, including alcohol use, and examination.

• Blood test for anemia and nutritional deficiency.

• Fecal analysis for the detection of undigested fat.

• Analysis of the culture of microorganisms inhabiting the intestines.

• Samples of exhaled air to detect lactose intolerance or excessive growth of bacteria in the small intestine.

• Biopsy of intestinal tissue( the sample can be taken during endoscopy, that is, by visual inspection of the upper part of the small intestine using a flexible tube with illumination).

• X-ray of the stomach and upper part of the small intestine using barium to get a clear image.

Treatment of

• In some cases, it is only necessary to exclude certain foods that cause or exacerbate symptoms for treatment. For example, people with lactose intolerance should avoid dairy products;patients with gluten disease can be cured by avoiding all food products containing gluten( a protein found in wheat, rye, oats, and barley).

• The underlying disease causing malabsorption must be identified and cured. For example, antibiotics are used to treat an infectious disease.

• Food supplements can be prescribed. Usually they include calcium, magnesium, iron and vitamins A, D, E and K.

• Pancreatic enzymes can be prescribed to make up for their under-production.

• Corticosteroids can improve absorption in certain inflammatory diseases.

• In many cases, foods high in carbohydrates and low in fat are recommended;such food is easier for the body to digest and suck.

Prevention

• Prophylaxis of insufficiency of absorption is possible only due to prevention of the underlying illness( eg, infection).

• Consult a doctor if diarrhea or other digestive problems persist for more than three days.