Medical dissolution of gallstones. Clinical experience of d-limonene as a simple, safe, and effective solvent. Retained gallstones in the bile ducts account for 60-70% of all the cases of postcholecystectomy syndromes. A solvent d-limonene preparation was injected directly to the biliary system of 200 patients to dissolve or disintegrate the retained gallstones. The outcomes were: retained stones completely disappeared in 96 cases (48%); partial dissolution in 29 (14.5%); chelating agent was also used with partial dissolution in 16 (8%); ineffective in 59 (24.5%). To make this method more effective, several guidelines should be observed including an in vitro trial dissolution test. Cautious observation for possible side effects and frequent hepatic and pancreatic function tests during the treatment with this preparation also should be performed. 