[COVID-19-associated diarrhea]

In addition to the typical clinical picture of respiratory symptoms and intoxication, the SARS-CoV-2 virus is also characterized by a gastroenterotropic effect. Diarrhea is one of the most common gastroenterological symptoms of COVID-19 and is detected, according to the various authors, in 2-49.5% of cases, including children. The presence of diarrhea aggravates the patient's clinical condition, limits the possibility of carrying out the necessary diagnostic manipulations, and complicates the selection of therapy. The article provides an overview of the scientific literature on the formation of diarrheal syndrome in patients with COVID-19. Objective. Analysis of scientific publications studying the pathogenesis, incidence, clinical features, aspects of diagnosis and therapy of diarrhea in patients with COVID-19. Material and methods. A search was made for scientific publications on the electronic resources PubMed, Google Scholar and eLIBRARY.ru. Results. The pathogenesis of diarrhea in a new coronavirus infection is complex and includes, among other things, the effect of the virus on the angiotensin-converting enzyme 2 receptors, inducing an inflammatory process in the gastrointestinal tract mucosa, neurotropic effect on the autonomic regulation of intestinal motor activity, disturbance of the colon microbiota, liver and pancreas damage. Another important pathogenetic aspect of diarrhea in COVID-19 is iatrogenic one, i.e. a side effect of drugs used in the treatment of a new coronavirus infection and its complications, and the activation of opportunistic clostridial intestinal flora against the background of antibiotic therapy. The variety of pathogenetic mechanisms of diarrheal syndrome formation allows us to speak of "COVID-associated diarrhea" as an independent clinical phenomenon characteristic for the new coronavirus infection. Mandatory diagnostic algorithm of a patient with COVID-19 and diarrhea is the fecal analysis test for toxins Cl. difficile, while the possibility of endoscopic examinations during the pandemic is limited. Compliance with the hygiene measures, diet correction and nutritional support, rational antibiotic therapy of COVID-19 complications, careful use of antiperistaltic antidiarrheal drugs, nonspecific therapy (antiviral, rehydration, adsorbents) are considered as the main therapeutic approaches for diarrheal syndrome against the background of COVID-19. The administration of probiotics and antibacterials should be considered in case of confirmed clostridial co-infection. Conclusion. Diarrhea is a frequent clinical manifestation of COVID-19 and can affect the course of the disease. The complex genesis of diarrheal syndrome requires further study of therapeutic strategies and nutritional support for patients after COVID-19.