The American Association for the Study of Trauma classifies rectal and rectosigmoid injuries into five grades based on severity and presence of devascularization. They are:
Grade 1 – laceration of partial thickness bowel wall or hematoma/contusion
Grade 2 – laceration of bowel wall less than 50% in circumference
Grade 3 – laceration of bowel wall greater than 50% in circumference but less than complete transection
Grade 4 – transection of bowel with extension into perineum
Grade 5 – devascularization of bowel segment
Very understandable classification. Need more information on colorectal injury