Features favouring ulcerative colitis over Crohn's disease
| Reliability/discriminant value | Feature | Figures | Evidence level | References |
|---|---|---|---|---|
| 1. Reliable | Diffuse crypt abnormalities within and between sites | 3C | EL1a RGA | 13 18 36 |
| Diffuse crypt abnormalities within a site | EL1b RGB | 18 | ||
| Crypt atrophy | 2D | EL1a RGA | 11 25 34 36 50 62 | |
| Abnormal crypt architecture | EL1a RGA | 11 25 63 | ||
| Villous or irregular mucosal surface | EL1a RGA | 11 25 | ||
| Mucin depletion | EL1a RGA | 3 11 36 63 | ||
| Absence of ileal inflammation | 3C | EL1b RGB | 64 | |
| 2. Reliable in some studies, but variably defined | Diffuse transmucosal chronic inflammation/diffuse inflammation/heavy diffuse transmucosal lamina proprial infiltrate/transmucosal lamina proprial hypercellularity | 2F | EL1b RGA | 3 11 36 50 |
| 3. Less evidence | Widespread cryptitis/‘general crypt epithelial polymorphs’ | EL1b RGD | 3 36 50 | |
| The following more prevalent distally than proximally: diffuse transmucosal inflammation; diffuse crypt changes; focal crypt changes | EL2b RGC | 36 |