| Extent |
Anatomy |
| E1 |
Ulcerative proctitis |
Involvement limited to the rectum (that is, proximal extent of inflammation is distal to therectosigmoid junction) |
| E2 |
Left sided UC (distalUC) |
Involvement limited to a proportion of the colorectum distal to the splenic flexure |
| E3 |
Extensive UC |
Involvement extends proximal to the splenic flexure |
|
