Nonalcoholic fatty liver disease (NAFLD) combines with a variety of liver pathologies, including hepatic steatosis, nonalcoholic steatohepatitis, fibrosis and cirrhosis, and acts as hepatic manifestation of metabolic syndrome. Not only the liver is a target organ in the formation of metabolic syndrome: also exist a possibility of gallbladder, pancreas and biliary tract steatosis. Fatty infiltration of the pancreatobiliary system associates with disturbance of digestive processes that promotes dysbiotic changes and intestinal disorders. Changes in intestinal microbiota, in turn, may induce systemic inflammatory response and promote NAFLD development and progression. Objective: to explore the structural and functional state of the pancreatobiliary system and changes of the enteric microflora in children with NAFLD. Methods. In 34 children with disorders of the gastrointestinal tract, we have determined controlled attenuation parameter by means of FibroScan. Assessment of functional status of biliary tract was performed using an ultrasound examination of the abdominal organs with test meal in order to determine gallbladder contractility and the sphincter of Oddi function. To characterize the state of the enteric microbiota, there was carried out a hydrogen breath test with glucose or lactose loading. Children were divided into groups according to the the transient elastography of the liver (FibroScan): the control group was represented by 21 patients without liver steatosis, the main group — 13 patients with liver steatosis. Results. Children with nonalcoholic fatty liver disease had signs of not only liver pathology, but also of the bile ducts and the pancreas. Biliary tract dysfunction in patients with NAFLD more often manifested as hypotension of the sphincter of Oddi and the gallbladder hypokinesia. Lesions of the pancreas function in children with NAFLD can be explained by the sphincter of Oddi disorders and manifestations of pancreatic steatosis. Intestinal pathology (irritable bowel syndrome and excessive bacterial growth) was significantly more common in the group of children with liver steatosis. Changes in the state of microflora of the small intestine were detected in 27.6 % of patients. The syndrome of excessive bacterial growth was observed significantly more in the group of patients with hepatic steatosis.