Blunt intestinal injury. Keys to diagnosis and management. Fifty-six patients with blunt intestinal injury seen during 39 months were reviewed for keys to diagnosis and treatment. Motor vehicle accidents were involved in 80% of the cases and seat/lap belts were in use 69% of the time. Blunt intestinal injury was the only abdominal injury in 70% of the cases. There were 42 perforations and 20 devascularizations; multiple injuries were common (27%). Abdominal tenderness was present on admission in 43 of 44 patients in whom a reliable examination was possible. Peritoneal lavage was positive in 13 (93%) of 14 patients. Computed tomography was falsely negative in three of four instances in which it was used. Perforations were most common in the upper and lower ends of the small bowel and in the sigmoid colon; devascularizations were most common in the distal ileum and sigmoid colon. Resection/anastomosis was performed in 38% of small-bowel perforations and in all small-bowel devascularizations. Resection/diversion was required in most colonic perforations (five of six patients) and devascularizations (four of six patients). There were five deaths (9%), none due to intestinal injury. There were seven complications related to intestinal injury. Diagnostic delay occurred in two patients; both had resultant morbidity. Blunt intestinal injury is associated with physical findings in conscious patients. Peritoneal lavage should be used when tenderness cannot be evaluated. Timely operative intervention minimizes morbidity and hospital stay. 