The role of citrate in oral rehydration therapy

Eleven patients had cholesterol gallstones and bile analysis revealed cholesterol crystals only in two and both types of crystals in six. Twelve patients had pigment stones; two had cholesterol crystals, three had both types of crystal and three had bilirubinate crystals only. Bile was obtained in three of the five patients with a blocked cystic duct; one of these patients with empyema of the gallbladder and cholesterol stones had bile cholesterol crystals. Inclusion of bilirubinate crystal analysis increased the sensitivity of diagnosing gallstones from 50% using cholesterol-crystal analysis alone to 66.7%. The use of an incubation period with re-examination of the supernatant also increased the diagnostic rate by 27%. The sensitivity of the test could be further improved by repeating the test on different days (Marks & Bonoorus, 1984). The finding of bilirubinate crystals only in 25% of patients with pigment stones (compared to none in those with cholesterol stones) might be of practical value as these patients would not be suitable for gallstone dissolution by methyl-tert-butyl-ether (Neoptolemos et al., 1986). In conclusion, bile-crystal analysis was found to be useful for identifying patients with gallstones. Although rather poor for gallstone-type identification, further refinements in technique are possible. Bile-crystal analysis should receive a wider application in clinical practice.