Injury Location Dictates Utility of Digital Rectal Examination and Rigid Sigmoidoscopy in the Evaluation of Penetrating Rectal Trauma

Penetrating pelvic injuries (specifically rectal) pose a difficult diagnostic challenge. Although management of these injuries, once recognized, can be straightforward, the consequences of a missed injury can be devastating. The purpose of this study was to evaluate the utility of digital rectal examination (DRE) and rigid sigmoidoscopy (RS) as screening tests for penetrating rectal injuries. Patients with full-thickness penetrating rectal injury over a 10-year period were identified. All underwent DRE and RS before exploration. Injury location was classified as intraperitoneal (IP) or extraperitoneal (EP). Overall sensitivities for DRE and RS were calculated as well as sensitivities for RS in the identification of IP versus EP injuries. Seventy-seven patients were identified. Overall sensitivity for DRE and RS was 51 per cent (95% CI: 37-65%) and 78 per cent (95% CI: 65-92%), respectively. Sensitivity of RS for identification of rectal injury based on anatomic distinction was 58 per cent (95% CI: 30-86%) for IP and 88 per cent (95% CI: 75-100%) for EP injuries. Anatomic location determines the value of preoperative screening tests for identification of penetrating rectal injuries. RS proved better than DRE for diagnosis. The greatest benefit was observed with EP injuries. The possibility of a missed IP injury associated with a negative screen should prompt exploration if clinical suspicion is high.