Bilateral stones and renal failure.

14 performed where necessary. Radiological examinations including intravenous urograms were done on 38 patients and retrograde pyelograms in 4. Biochemical tests including the serum creatinine, blood urea and electrolytes, uric acid, calcium and phosphates were performed periodically. The presence of calculi was diagnosed from radiological studies, operative findings and from a clear history of passing out of stones.