Trauma to the Colon and Rectum

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How do most colon injuries occur?

Nearly all (>95%) colon injuries are caused by penetrating trauma from a gunshot, a stab wound, an iatrogenic injury, or a sexual injury. Blunt colonic trauma is rare and usually results from seat belts during motor vehicle crashes.

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How are colon injuries diagnosed?

They are usually diagnosed during laparotomy for penetrating trauma. For patients in whom the need for laparotomy has not been established, a rectal examination may show blood in the stool, which suggests a left-sided or rectal injury. Elevated white blood cell counts or enzyme levels (amylase, alkaline phosphatase) may reflect a bowel injury. While no longer commonly performed, fecal material in diagnostic peritoneal lavage is highly suggestive of a bowel injury. Imaging findings that are concerning for a colonic injury include free air, extravasation of contrast, retroperitoneal gas, or fluid adjacent to the colon. All significant injuries are generally clinically manifest within 18 hours of injury.

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How are colon injuries graded?

• Grade I: Contusion or hematoma without devascularization or partial-thickness laceration

• Grade II: Laceration <50% circumference

• Grade III: Laceration >50% circumference

• Grade IV: Transection of the colon

• Grade V: Transection with segmental tissue loss or devascularization

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What are three primary surgical options for managing a colon injury?

• a.

  Primary repair: Nondestructive colon wounds without devascularization and involving <50% of the bowel wall can be primarily repaired with suture.

• b.

  Resection with primary anastomosis: Destructive wounds that feature devascularization or involve more than 50% of the bowel wall should be resected. In these cases, it is safe to perform a primary reanastomosis in patients with good hemodynamic status, minimal contamination, and minimal comorbidities.

• c.

  Resection with colostomy formation: Some patients are too sick to undergo primary anastomosis. These are the patients that are in persistent shock, coagulopathic, multiply injured, or affected by other comorbidities. In this situation, it is appropriate to perform a resection with a colostomy.

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