Urine specimens were collected from 100 normal individuals and 100 stone patients and analysed spectrophotometrically for common stone promoters like oxalate, calcium, uric acid and phosphate and stone inhibitors like citrate and magnesium and creatinine. After overnight urine concentration, an oral water load was given to induce a diuresis. Hypocitraturia and hyperoxaluria were the common abnormalities found in the stone formers. Stone formers had significantly higher urinary oxalate, calcium and uric acid than normal individuals. Citrate / calcium and magnesium / calcium ratio were significantly low in stone formers and seems to be a risk factor for stone formation. The urinary calcium / creatinine ratio was found to be high when the creatinine concentration was low, but usually normal when the creatinine concentration was high. The results suggest that if the urinary calcium / creatinine ratio of random urine specimens is used as a screening procedure to detect hypercalciuria.
