Level reached during flexible sigmoidoscopy between 1993 and 1998, as determined by the endoscopist
| Site reached | No | % |
| Terminal ileum | 15 | 1.6 |
| Caecum | 18 | 2.0 |
| Ascending colon | 30 | 3.3 |
| Hepatic flexure | 31 | 3.4 |
| Transverse colon | 71 | 7.8 |
| Splenic flexure | 229 | 25.0 |
| Descending colon | 681 | 74.4 |
| Sigmoid colon | 904 | 98.8 |
| Rectum | 915 | 100 |