Grading of acute intestinal damage
| Global assessment | Criteria |
| 0: None | No inflammation |
| I: Minimal/indeterminate | Scattered infrequent inflammatory infiltrate in a minority of crypts, which is minimal |
| II: Mild | Inflammatory infiltrate in 50% of the crypts, which is generally mild, and confined within the mucosa epithelium with mild architectural distortion |
| III: Moderate | Inflammatory infiltrate involving most of the crypts, and associated with architectural distortion (villous blunting and focal mucosal atrophy/erosion) and luminal inflammatory exudate |
| IV: Severe | Extensive inflammatory infiltrate (large lymphoid aggregates) with expanding into the lamina/muscular propria, and associated with prominent mucosal ulceration/denuding, muscular wall necrosis, and/or perforation |
| Global assessment | Criteria |
| 0: None | No inflammation |
| I: Minimal/indeterminate | Scattered infrequent inflammatory infiltrate in a minority of crypts, which is minimal |
| II: Mild | Inflammatory infiltrate in 50% of the crypts, which is generally mild, and confined within the mucosa epithelium with mild architectural distortion |
| III: Moderate | Inflammatory infiltrate involving most of the crypts, and associated with architectural distortion (villous blunting and focal mucosal atrophy/erosion) and luminal inflammatory exudate |
| IV: Severe | Extensive inflammatory infiltrate (large lymphoid aggregates) with expanding into the lamina/muscular propria, and associated with prominent mucosal ulceration/denuding, muscular wall necrosis, and/or perforation |