Renal lithiasis in Lebanon: I--the chemical types of urinary calculi.

The results of chemical analyses of 429 urinary calculi are presented and classified according to chemical composition. Some of the general features of the different chemical types of the stones are discussed. Although the general distribution of the chemical types of stones in Lebanon is essentially similar to that reported from other countries, the two striking features of this series are: (1) a relatively lower incidence of infection stones (i.e. stones containing magnesium ammonium phosphate) and (2) a relatively higher incidence of stones containing a mixture of uric acid and calcium oxalate and/or calcium phosphate.