Table 1.
Descriptors and definitions
| Descriptor (score most severe lesions) | Likert scale anchor points | Definition |
| Vascular pattern | Normal (1) | Normal vascular pattern with arborisation of capillaries clearly defined |
| Patchy loss (3) | Patchy loss or blurring of vascular pattern | |
| Obliterated (5) | Complete loss of vascular pattern | |
| Mucosal erythema | None (1) | The colour of the mucosa is normal |
| Light red (3) | Some increase in colour of the mucosa that is probably abnormal, but would be best compared side by side with a normal examination | |
| Dark red (5) | Red or crimson colour of the mucosa that is similar to blood—that is, clearly abnormal even if not compared with a normal examination (does not include intramucosal haemorrhage) | |
| Mucosal surface (Granularity) | Normal (1) | Smooth mucosa with a sharp light reflex, similar to a polished surface |
| Granular (3) | Mucosal surface diffuses reflected light causing minor variation in the surface | |
| Nodular (5) | Evident nodular variation in mucosal surface | |
| Mucosal oedema | None (1) | Normal appearance: no white or yellow substance visible |
| Probable (3) | Slight swelling and thickening of mucosa | |
| Definite (5) | Marked thickening and oedema of the mucosa with blunting of the mucosal folds | |
| Mucopus | None (1) | Normal appearance: no white or yellow substance visible |
| Some (3) | White or yellow deposits on the mucosa unrelated to any bowel preparation | |
| Lots (5) | Mucopus substantially covering the mucosal surface unrelated to any bowel preparation | |
| Bleeding | None (1) | No visible blood |
| Mucosal (2) | Some spots or streaks of coagulated blood on the surface of the mucosa ahead of the scope, which can be washed away | |
| Luminal mild (3) | Some free liquid blood in the lumen | |
| Luminal moderate (4) | Frank blood in lumen ahead of endoscope or visible oozing from mucosa after washing intraluminal blood | |
| Luminal severe (5) | Frank blood in the same lumen with visible oozing from a haemorrhagic mucosa | |
| Incidental friability | None (1) | No bleeding or intramucosal haemorrhage before or after passage of the endoscope |
| Mild (2) | No bleeding at the site of assessment before, but minor bleeding or intramucosal haemorrhage after, passage of the endoscope | |
| Moderate (3) | Intramucosal haemorrhage without overt bleeding before passage of the endoscope | |
| Severe (4) | Overt bleeding after passage of the endoscope | |
| Very severe (5) | Overt bleeding from the mucosa | |
| Contact friability | None (1) | No bleeding from the mucosa after light touch with closed biopsy forceps |
| Probable (3) | Intramucosal haemorrhage or minor bleeding after light touch with closed biopsy forceps | |
| Definite (5) | Overt bleeding mucosa after light touch (within 10 s) with closed biopsy forceps | |
| Erosions and ulcers | None (1) | Normal mucosa, no visible erosions or ulcers |
| Erosions (2) | Tiny (≤5 mm) defects in the mucosa, of a white or yellow colour with a flat edge | |
| Superficial ulcer (3) | Larger (>5 mm) defects in the mucosa, which are discrete fibrin-covered ulcers in comparison with erosions, but remain superficial | |
| Deep ulcer (4) | Deeper excavated defects in the mucosa, with a slightly raised edge | |
| Extent of erosions or ulcers | None (1) | None seen during endoscopy |
| Limited (2) | <10% of the affected mucosa | |
| Substantial (3) | 10%–30% of the affected mucosa | |
| Extensive (4) | >30% of the affected mucosa |
* An additional descriptor attempted to describe the transition from abnormal to normal mucosa, but was discarded during phase 1 on the basis that it defied definition. Erosions and ulcers had four (response) levels while the others had five because the expert panel were unable to form a range of five responses with meaningful or measurable distinctions between 2 and 3 or 3 and 4.