140 cholecystectomized patients were subjected to out-patient clinical follow-up (follow-up range 15.5 +/- 7.1 months) as were 45 patients given various operations on the digestive tract. The controlled study was divided into two phases: epidemiology and therapy. The results of the epidemiological trial clearly showed that in about half the cases treated cholecystectomy leaves certain problems of digestive dysfunction (dyspeptic-pain syndrome) unresolved but does not cause new symptoms. Hence there is no justification for the term "post-cholecystectomy syndrome". A double blind therapeutic trial confirmed the efficacy of UDCA in the treatment of dyspepsia in cholecystectomized patients (p = 0.03) but showed that it has little influence on the pain factor (p = 1.00).