Considering the causes of diarrhea in a newborn, specialists pay attention to possible congenital dyspeptic disorders, which are manifested by chronic diarrhea in newborns and constitute a group of hereditary enteropathies.
Most of the cases of intestinal enzyme pathologies (detected in one of 1-2.5 thousand newborns) occur in lactase deficiency in children (hypolactasia) - that is, a low level of the specific enzyme lactase (galactosidase), which is necessary for the hydrolysis of lactose (milk sugar). Also, this pathology is called lactose intolerance, and the pathogenesis of diarrhea due to it is due to the increase in osmotic pressure in the intestine (due to the accumulation of unsplit milk sugar) and the emergence into its lumens of a fluid that increases the volume of feces and dilutes their consistency.
Food intolerances and allergies can also be triggers of an intestinal disorder in an infant, and more often for this reason diarrhea occurs in a newborn with artificial feeding, as well as diarrhea in a newborn with mixed feeding. The main cause is an allergy to cow milk (whey proteins, which are part of the milk formula); while specific IgE against dairy proteins is detected in the blood. There may be an allergic reaction to soy lecithin or maltodextrin (corn starch syrup) in certain mixtures that replace breast milk. Read more - Allergy to milk in children
The products used by the lactating mother to cause diarrhea in the newborn: milk and all dairy products (including cottage cheese, cheese, butter, etc.), soy products and soybean meal, wheat, corn, chicken eggs, seafood, nuts, peanuts, strawberries, citrus fruits .
But the key causes of diarrhea in newborn pediatricians see in the intestinal dysbiosis, more precisely, in the inadequate composition of the intestinal microbiota of the baby, which is transmitted at birth from the mother. It is known that the digestive tract of the fetus is sterile in the womb, but a few hours after birth the child acquires a whole "set" of microorganisms. In this case, the intestinal microflora of newborns emerging as a result of natural childbirth is similar to the vaginal microflora of the mother (including Lactobacillus acidophilus, Bifidobacterium, Escherichia coli and Enterococcus). But in cesarean-borne sections of the microflora is closer to the microbiota of the mother skin and the environment and contains, in particular, the bacteria Clostridium difficile and Streptococcus spp. With significant colonization of the intestine with clostridia, the pathogenesis of neonatal diarrhea is associated with the production of enterotoxins (TcdA and TcdB) which damage the intestinal mucosa. Often, cases of neonatal intestinal infection with lesions of Staphylococcus aureus, whose toxins cause diarrhea in the newborn with mucus and atrophy of the villi of the intestine, which slows the growth of the child during the first weeks of life.
Why diarrhea in a newborn during breastfeeding occurs in 3-6 times less often than diarrhea in a newborn with artificial feeding? Because when breastfeeding in the digestive tract of the baby, bifido- and lactobacilli are sufficient, the interaction of which leads to the production of acids (acetic, oily and lactic), which protect the intestines from pathogens. Moreover, mother's milk has antimicrobial antibodies to the mother (secretory IgA), which reduce the growth of facultative anaerobes and prevent the development of enterovirus infections.
Very often causes diarrhea in newborn - infection p otavirusami that are highly contagious and easily transmitted by the fecal-oral route. Diarrhea and vomiting in a newborn due to rotavirus gastroenteritis account for 40% of all cases. In addition, gastroenteritis with watery diarrhea and frequent vomiting causes norovirus and astrovirus.
To microorganisms that can cause diarrhea with mucus, vomiting, intestinal spasms and febrile state in a newborn, enter enterobacteria Klebsiella oxytoca, Enterobacter cloacae, Citrobacter freundii, Shigella spp and Salmonella spp. For example, salmonella usually enters the intestine of a newborn when passing through the birth canal of the mother, which can be an asymptomatic carrier of the infection.
Risk factors for the development of diarrhea in newborns: a deficiency of zinc in the body (reducing the function of immunity) and insufficient intake of vitamin A. The use of antibacterial drugs by the mother or their appointment to the child in the postpartum period in 90% of cases guarantees diarrhea in a newborn after antibiotics, leading to a change in the composition of the intestinal microbiota .