[Medical treatment of cholelithiasis. I. Bile acids]

Gallstones constitute an important health problem for its prevalence and the cost of its definitive treatment, cholecystectomy. Thus, medical therapy is a necessary and desirable goal. In this study the different means for the non-surgical treatment of gallstones are reviewed. In this first part the pharmacological basis is described as well as the selection of patients. The litholytic mechanism of bile acids, its efficacy and the causes of therapeutic failure are describe.