Objectives – the review presents the analysis of the main changes in Rome IV. The subsequent Rome IV consensus focused on the etiology, pathogenesis, diagnosis and differential diagnosis of the functional gastrointestinal disorders. It updated some definitions of the functional gastrointestinal disorders; opioid-induced constipation was set as a separate disorder; functional abdominal distention was considered specific for functional abdominal bloating as both disorders are often combined and do not replace each other. The functional gastrointestinal disorders still remain of the high medico-social importance as they are endemic, refractory and cause long-term disability.