The composition of biliary calculi in patients with juxtapapillary duodenal diverticula.

Biliar calculi from 32 patients with juxtapapillary duodenal diverticula were analyzed by quantitative infrared spectroscopy. In 22 of the patients the calculi were classified as pigment stones and in 10 as cholesterol stones. Calcium bilirubinate was the main component in the pigment stones, with a median value of 45%; the median cholesterol content was 7.5%. In the cholesterol stones median calcium bilirubinate content was 1% and median cholesterol content 95.5%. Calcium carbonate was found in small amounts in only nine of the calculi. The findings support our theory that the pigment calculi in patients with juxtapapillary diverticula are caused by ascending infections to the bile ducts with intestinal beta-glucuronidase-producing bacteria. Beta-glucuronidase will split the conjugated bilirubin in bile into glucuronic acid and unconjugated bilirubin, which in turn combine with calcium to form insoluble calcium bilirubinate.