Aim — the objective of the present study was to evaluate the therapeutic effectiveness of trimebutine (trimedat) when used for the treatment of the biliary pain syndrome and the maintenance of remission of the disease in the patients presenting with functional gallbladder disorders and sphincter of Oddi (SO) incompetence. Material and methods. A total of 85 patients suffering from the biliary pain syndrome meeting the Rome IV diagnostic criteria of the expert panel consensus were available for the examination. In 40 of them, this condition was associated with the impairment of the gallbladder (GB) function and in the remaining 45 ones with sphincter Oddi (SO) incompetence. The effectiveness of the treatment was evaluated based on the degree of manifestation of duodenal reflux, results of ultrasound studies and oral meal challenge taking into consideration dynamics of pain and dyspeptic syndromes within 3 weeks after the onset of trimebutine intake and 3 weeks after the termination of therapy. The immunohistochemical studies of the mucous membrane biopsy samples obtained from the antral section of the stomach were carried out on the first and the last days of the treatment making use of monoclonal murine anti-motilin and anti-vasoactive intestinal peptide antibodies. Results. The 3 week course of trimebutine treatment made it possible to eliminate the biliary pain syndrome in 81.2% of the patients presenting with GB and SO functional disorders. The therapeutic effect of the medication persisted as long as 3 weeks after the withdrawal of the treatment in 98.8% of these patients. The effectiveness of therapy was not significantly different in the patients with hypo- and hypermotor dysfunctions of the biliary tract. The study has demonstrated that the patients with the impairment of the gallbladder function and sphincter Oddi (SO) incompetence had an originally reduced motilin level that gradually increased during the period of treatment with trimebutine simultaneously with normalization of the motor function of GB and SO and elimination of duodenogastric reflux. Conclusion. Trimebutine efficiently eliminates biliary pain syndrome and exerts the modulating action on the motility of the biliary tract which allows to consider this preparation as a therapeutic pharmaceutical agent for the initial treatment of the patients presenting with the biliary pain syndrome associated with the functional disorders of the gallbladder and the sphincter of Oddi.