AASTBowel Injury ScalePatient Education GuideHighest Finding (Imaging/OR)IContusion or hematoma without devascularizationIIPartial thickness laceration without perforationIIILaceration with perforation <50% circumferenceIVLaceration with perforation ≥50% circumference OR TransectionVTransection with massive tissue loss OR Devascularized segmentDetermine GradeBowel Injury GradingSelect the highest radiologic or operative finding to determine the AAST severity grade.Guidelines & EvidenceWhen to UseHow it WorksClinical PearlsNext StepsThe EvidenceOrigins & HistorySection 1When to UseSection 2How it WorksSection 3Clinical PearlsSection 4Next StepsSection 5The EvidenceSection 6Origins & HistoryVerifiedLast Review: 2026When to UseWhen to UseBlunt abdominal trauma with suspected hollow viscus injury (e.g., seatbelt sign, high-speed MVC)Penetrating abdominal trauma (stab wounds, gunshot wounds) involving bowel trajectoryUnexplained peritonitis following traumaFree intraperitoneal air or fluid without solid organ injury on CT imagingIntraoperative identification of bowel injury requiring classificationTrauma registry documentation and prognostic stratificationClinical UtilityStandardizes description of bowel injuries across trauma systemsGuides operative vs non-operative management decisionsHelps determine need for resection vs primary repair vs diversionPredicts morbidity such as leak, abscess, and sepsisFacilitates communication between trauma surgeons and multidisciplinary teamsLimitationsDoes not incorporate degree of contamination or time to surgeryDoes not directly account for patient physiology or shock stateLess predictive in polytrauma where competing injuries dominate outcomesInter-observer variability in CT-based detection of bowel injuryContraindications / ExclusionsNon-traumatic bowel perforation (e.g., malignancy, ulcer)Isolated mesenteric injuries without bowel wall involvementPostoperative or iatrogenic bowel injuriesLast Comprehensive Review: 2026