RESUMEN
Of 1,211 patients with urolithiasis treated at this institution over a nine years period, there were 77 (6.4%) pediatric cases. The commonest age group was 6-10 years (55.8%). Male:female ratio was 7.6:1. Hindus constituted 72.7% of the patients. There was no significant seasonal variation. The commonest site was urinary bladder (67.5%). The upper: lower urinary tract stone ratio was 1:2.85. Majority belonged to the lower-middle or poor income groups having a cereal based diet with minimal or poor protein intake. The common constituents of stones were calcium (98.7%), oxalate (87%), phosphate (84.4%) and uric acid (76.6%). Of all these, uric acid had the richest concentration (grade of ++ or more) in 93.2%. Only 4 stones (5.2%) were "pure": calcium oxalate--3 and calcium phosphate--1; whereas 73 (94.8%) were mixed stones. Of these, 9 (11.7%) were "predominant" mixed stones, with only one constituent having rich concentration (grade of ++ or more) and all others being either trace or +. The rest 64 (83.1%) were "heterogenous" mixed stones having rich concentration of more than one constituent.