Diarrhea (diarrhea) in a child

Diarrhea, or diarrhea, is the repeated passage of loose, watery stool. Diarrhea can sometimes be so watery that the stool can be mistaken for urine.

Diarrhea is frequent bowel movements with a change in the nature of the stool, from mushy to watery. Diarrhea is caused by accelerated passage of contents through the intestines, slow absorption of fluid, and increased mucus formation. Healthy children, especially infants, sometimes have stool after each feeding or meal, which is caused by the gastroleocecal or gastroleocolic reflex. A distinction is made between diarrhea with a large (in diseases of the stomach, pancreas, celiac disease) amount of feces and diarrhea with a small amount (in peptic ulcer disease, colitis with predominant damage to the distal parts of the intestine, myxedema).

Remember: loose stools are normal for infants. Sometimes, when feeding cow's milk, the baby's stool is green - this is not dangerous. Diarrhea in a child may be the first symptom of a urinary tract infection. Frequent mushy stools (4 to 6 times a day) can be observed in normal infants; this should not cause concern unless there are signs of anorexia, vomiting, weight loss, slow weight gain, or blood in the stool. Frequent stools are typical for breastfed children, especially if they are not receiving complementary foods. The danger of diarrhea in children at any age is considered depending on whether it is acute (less than 2 weeks) or chronic (more than 2 weeks).

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Causes of Diarrhea in Children

Acute diarrhea (diarrhea) in a child often has infectious causes, especially if the onset is sudden or combined with vomiting, bloody stool, fever, anorexia. The diagnosis is made clinically, treatment is supportive until spontaneous improvement occurs.

Chronic diarrhea is a more serious condition. Causes include celiac disease, cystic fibrosis of the pancreas, allergic gastroenteropathy, and disaccharidase deficiency. Inflammatory bowel disease and some infections can also cause diarrhea.

In celiac disease, the gluten fraction of wheat protein causes damage to the intestinal mucosa and impaired fat absorption, leading to malabsorption, anorexia, and large, foul-smelling stools. Stool changes begin when wheat flour products and other gluten-containing products are introduced into the child’s diet.

Cystic fibrosis causes pancreatic insufficiency, which leads to a deficiency of trypsin and lipase, which in turn leads to large losses of protein and fat in the stool, and therefore to malabsorption and delayed physical growth. The stool is large and often foul-smelling. Children with cystic fibrosis often suffer from respiratory problems and growth retardation.

In disaccharidase deficiency, intestinal mucosal enzymes such as lactase, which breaks down lactose into galactose and glucose, may be congenitally absent or may develop a temporary deficiency after a gastrointestinal infection. Improvement after eliminating lactose (or other carbohydrates) from the diet or after introducing lactose-free formulas reliably confirms the diagnosis.

In allergic gastroenteropathy, cow's milk protein may cause diarrhea, often with vomiting and blood in the stool, but intolerance to the carbohydrate fraction of the food eaten should also be suspected. Symptoms are often significantly reduced by introducing soy formula instead of cow's milk formula and return when cow's milk is reintroduced into the diet. Some children with cow's milk intolerance also do not tolerate soy, so the formula should contain hydrolyzed protein and should not contain lactose. Often spontaneous improvement occurs by the age of one year.

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Gastroenteritis

Gastroenteritis is an infectious lesion of the small intestine, accompanied by diarrhea and vomiting. The main danger in this case is dehydration and disruption of the water-electrolyte balance. The most common cause of such gastroenteritis is rotavirus infection; the disease is often combined with otitis media or upper respiratory tract infection. If the child is not in a state of dehydration, treatment measures consist of frequent weighing of the baby (in order to timely track the progression of the disease and quantitatively assess the degree of dehydration, if, of course, the child's previous initial weight is known); the child is stopped from giving both milk and solid food, replacing all this with rehydration mixtures given orally (for example, Rehidrat).

If the child is given sweet water, three full (but not topped) teaspoons of sugar (3x5 ml) should be added to 200 ml of water and given at a rate of 150 ml/kg per day. Experience has shown that if the child feels well, adding salt is rarely necessary, and mothers should not add salt to the portion for feeding the child - this is dangerous. After 24-48 hours of abstinence from milk, it should be gradually given again. If the child is breastfed and his condition is not very serious, then you can allow him to continue breastfeeding (so that he receives antibodies from the mother and to maintain lactation in the mother).

Stool samples from a sick child should be sent to a laboratory to be tested for the presence of worm eggs, cysts and parasites.

Causes of secretory diarrhea in a child

Usually these are infections: bacterial (Campylobacter, Staphylococcus, E. coli, and in poor sanitary conditions Salmonella, Shigella, Vibrio cholerae ), giardiasis, rotavirus infection, amebiasis, cryptosporidiosis. Secretory diarrhea can also be caused by inflammatory bowel diseases.

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Other causes of diarrhea in children

In children of nursery age, diarrhea may be associated with "trips for peas and carrots", the cause of which is increased intestinal motility. Such diarrhea usually gradually passes on its own. Diarrhea may be caused by an allergy or enzyme deficiency (celiac disease, intolerance to disaccharides, galactose, lactose, glucose). The test for detecting this pathology consists of mixing 5 drops of stool with 10 drops of water, followed by using a Clinitest tablet. Diarrhea may also be caused by a deficiency of some vital substances - copper, magnesium and vitamins, as well as kwashiorkor.

Causes of bloody diarrhea in a child

These include Campylobacter infection, necrotizing enterocolitis (in newborns), intussusception, pseudomembranous colitis, inflammatory bowel disease (rare, even in older children).

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Mechanisms and pathogenesis of diarrhea

Intestinal hypersecretion is caused by disturbance of electrolyte transport in the intestine. The ratio of absorption and secretion is determined by the total flows on the enterocyte; they are regulated by neuroendocrine mediators, hormones and other biologically active substances.

The main causes of hypersecretion or secretory diarrhea are:

• bacterial exotoxins (enterotoxins);
• colonization of the small intestine by microorganisms, and in connection with this, the accumulation of deconjugated and dehydroxylated bile acids, hydroxylated fatty acids, and bacterial enterotoxins;
• bile acids;
• long chain fatty acids;
• gastrointestinal hormones (secretin, VIP, etc.);
• prostatandins; serotonin; calcitonin;
• laxatives containing anthraglycosides (senna leaves, buckthorn bark, rhubarb, etc.), castor oil, antacids containing magnesium salts, antibiotics (clindamycin, lincomycin, ampicillin, cephalosporins), antiarrhythmic drugs (quinidine, propranolol), digitalis, drugs containing potassium salts, artificial sugar (sorbitol, mannitol), chenodeoxycholic acid, cholestyramine, sulfasalazine, anticoagulants.

Secretory diarrhea also includes diarrhea associated with cholera, in which this process is most pronounced. Cholera endotoxin, bacterial toxins, etc. increase the activity of adenyl cyclase in the intestinal wall with the formation of cAMP, resulting in an increase in the volume of secreted water and electrolytes. In this case, large amounts of sodium are secreted, so that, despite the functional ability of the colon to retain sodium and secrete potassium, sodium losses in secretory diarrhea exceed potassium losses.

Free intracellular calcium has the property of reducing absorption and stimulating the secretion of sodium and chlorine. Therefore, calcium channel blockers have an antidiarrheal effect.

An increase in osmotic pressure in the intestinal cavity is observed with impaired digestion and absorption of carbohydrates, as well as with increased intake of osmotically active substances into the intestine (saline laxatives, sorbitol, etc.). Unabsorbed disaccharides lead to osmotic retention of water in the intestinal lumen. Since the mucous membrane of the small intestine is freely permeable to water and electrolytes, osmotic (PI) balance is established between the small intestine and plasma. Sodium is actively retained in the large intestine, therefore, with osmotic diarrhea, potassium is lost less than sodium.

Acceleration of transit of intestinal contents is caused by hormonal and pharmacological stimulation of transit (serotonin, prostaglandins, secucim, pancreozymin, gastrin); neurogenic stimulation of transit - acceleration of the evacuatory activity of the intestine (neurogenic diarrhea), an increase in intra-intestinal pressure (irritable bowel syndrome).

Intestinal hyperexudation is observed with inflammatory changes in the mucous membrane of the colon (dysentery, salmonellosis, etc.).

What to do if a child has diarrhea?

Anamnesis

The history focuses on the nature and frequency of stools, as well as associated symptoms and signs. Vomiting or fever indicate a gastrointestinal infection. A thorough food history is essential. Diarrhea that began after the introduction of semolina porridge indicates celiac disease, while changes in stool pattern with certain foods indicate food intolerance. Persistent blood in the stool indicates the need for a thorough search for more serious infections or gastrointestinal diseases.

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Inspection

The examination focuses on the appearance and signs of dehydration, growth stimuli, and abdominal inspection and palpation; failure to thrive indicates a more serious disorder. The respiratory system should also be assessed in children suspected of having cystic fibrosis.

Laboratory and instrumental examination

The examination is prescribed if the anamnesis and examination indicate a chronic disease. The level of electrolytes is determined if the child is dehydrated; the level of sodium and chlorine in sweat is determined if cystic fibrosis is suspected; if an infectious process is suspected, an examination for viruses, bacteria and parasites is carried out; stool pH is measured if disaccharidase deficiency is suspected. In celiac disease, an elevated level of specific antibodies is determined. Dietary changes can be used for both diagnosis and treatment.

Treatment of diarrhea in a child

Supportive treatment of diarrhea consists of providing adequate oral (or, less commonly, intravenous) rehydration. Antidiarrheal agents (eg, loperamide) are generally not recommended for infants and young children.

In chronic diarrhea, adequate nutrition should be maintained, especially the intake of fat-soluble vitamins. In diseases, special treatment methods are prescribed (for example, a gluten-free diet for celiac disease).