| Urological history | Number | Percentage (%) |
| Lombotomy | 6 | 20.0 |
| Urinary bilharzia | 2 | 6.7 |
| Percutaneous nephrolithotomy | 2 | 6.7 |
| Extracorporeal lithotripsy | 1 | 3.3 |
| Semi-rigid ureteroscopy | 1 | 3.3 |
| Without urological history | 18 | 60.0 |
| Total | 30 | 100 |