Clinical Practice Guidelines of the Scientific Society for the Clinical Study of Human Microbiome, of the Russian Gastroenterological Association and the Russian Society for the Prevention of Noncommunicable Diseases on the Diagnosis and Treatment of <i>Clostridioides difficile</i> (<i>C. difficile</i>)-associated Disease in Adults

А im: the clinical practice guidelines intended for gastroenterologists, internal medicine specialists, infectious disease specialists, general practitioners (family doctors), coloproctologists, surgeons and endoscopists present modern methods of diagnosis, prevention and treatment of C. difficile -associated disease. Key points. C. difficile -associated disease is a disease that develops when the diversity of the intestinal microbiota decreases and C. difficile excessively colonizes the colon, the toxins of which damage the intestinal muco-epithelial barrier, followed by the development of inflammation in the colon wall, with diarrhea being a characteristic clinical manifestation. The clinical presentation of the disease can vary from asymptomatic carriage, mild to moderate diarrhea that resolves on its own, to profuse watery diarrhea and pseudomembranous colitis with development of life-threatening complications. The diagnosis of C. difficile -associated disease is based on an assessment of the clinical presentation, medical history, an objective examination of the patient and laboratory stool tests. The disease severity is determined by clinical symptoms and laboratory findings. Additional diagnostic methods that are used according to indications and contribute to the assessment of severity include endoscopy of the colon and abdominal cavity imaging methods. Treatment should be initiated in cases of characteristic clinical presentation of C. diffi cile -associated disease and positive laboratory stool testing. The choice of drug and treatment regimen depends on the severity of the episode, the presence of complications, and whether the episode is initial, recurrent, or reinfection. Conclusion. Determination of target groups of patients for the diagnosis of clostridial infection is important in preventing overdiagnosis and subsequent unnecessary treatment. Timely diagnosis and treatment of C. difficile -associated disease help avoiding the development of life-threatening complications and improve the prognosis and quality of life of patients.