Rectal injuries are rare and are usually associated with penetrating trauma or significant pelvic fracture from blunt injury. Diagnosis starts with physical exam including inspection for signs of trauma as well as a digital rectal exam looking for blood, bony protuberance and abnormal sphincter tone. Normal digital rectal exam does not exclude injury.
Imagining is important in making the diagnosis.
“Findings on CT associated with rectal injury include a wound tract extending to the rectum, a full-thickness wall defect, perirectal fat stranding, extraluminal free air, intraperitoneal free fluid, and hemorrhage within the bowel wall….A CT with any suggestion of rectal injury should therefore be followed up with rigid proctoscopy to confirm the diagnosis and location of injury, as a combination of CT and endoscopy has a sensitivity of 97% in the diagnosis of rectal injury.”
References
Contemporary diagnosis and management of colorectal injuries: What you need to know
