Composition of urinary calculi collected in the Durban area.

Three hundred urinary calculi were collected in the Durban area during the period August 1979--August 1980. Analysis by the X-ray diffraction method showed that their composition is generally similar to that found in the USA and UK. The incidence of uric acid, present in 17% of the calculi, is higher than that found overseas. There is a significantly higher incidence of calcium oxalate in calculi from Indians (83% v. 70% in Whites) while there is a significantly higher incidence of urinary apatite in Whites (35% v. 21% in Indians).