| Bismuth classifications | Number of cases (n) | Percentage (%) |
| Bismuth Grade-1 | 1 | 4% |
| Bismuth Grade-2 | 11 | 36% |
| Bismuth Grade-3 | 13 | 44% |
| Bismuth Grade-4 | 4 | 12% |
| Bismuth Grade-5 | 1 | 4% |