The objective: to investigate the level and role of enteropathogen ic Escherichia coli in the development of acute enterocolitis (EPEC).Patients and methods. There was performed a prospective study of 153 people with suspected escherichiosis. Stage of screened 95 patients in whom bacteriological by allocated and identified from the lumen of the colon (LC), enteropathogenic (EPEC), enterotoxigenic (ETEP), enteroinvasive (EIEP), Enterohaemorrhagic (EHEC), and/or enteroaggregative (EACP) of Escherichia coli. Also pay attention to the presence of other pathogens (Salmonella, Shigella, Campylobacter, etc.), when the additional detection of patients excluded from the study. The patients' age from 25 to 52 years (aver age 38,66±3,11 years). Among the surveyed were 62 women (65,26%) and 33 men (of 34.74%).Results. It was revealed that obtained in patients contamination of the habitat of cavity TK pathogenic Escherichia the first leads to violation of the quantitative composition of the normal microbiota of the biotope through the adoption of the Escherichia coli and other antimi crobial substances that limit the growth and reproduction of bifi dobacteria and lactobacilli and promotes the proliferation of oppor tunistic enterobacteria, Staphylococcus, peptococcus, Clostridium, etc.. In the result of the study it was found that on the background of disturbed microbiocenosis implemented pathogenic properties of EPEC, ETEP, EIEP and EHEC.Conclusion. It was established that enteropathogenic E. coli (EPEC) causes acute diarrheal escherichiosis in 41.05% patients, enterotoxi genic Escherichia – in 29.45% subjects, enteroinvasive E. coli – in 23.16% patients and enterohemorrhagic E. coli – in 11.58% cases. Clinical manifestation of acute diarrheal scherichiosis is polymorphic and depends on the agents' biology and macroorganism immune status. Acute colienteritis was diagnosed in 57 (60.0%) persons, dysentery like clinical variant of the disease – in 24 (25,26%) persons, cholera like disease clinical manifestation – in 14 (14.74%) patients. Acute diarrhea scherichiosis develops on basic taxonomic composition and population microbiota of the distal colon violation.