Number of stones: 1 stone: 36 (81.8%); 2 stones: 7 (15.9%); 3 stones: 1 (2.3%)... Stone site: lower calyx 9 (20.5%); middle calyx 4 (9.1%); upper calyx 1 (2.3%); renal pelvis: 26 (59.1%); pelvis and lower calyx: 4 (9.1%).