Radiopaedia’s Black Friday Course Sale continues! SHOP NOW

Traumatic small bowel perforation

Case contributed by Dr Dayu Gai


This patient was riding a motorcycle when he mounted a footpath, striking a pedestrian and then a pole. The patient described lower abdominal pain on arrival at the hospital. A CT trauma series was performed.

Patient Data

Age: 90
Gender: Male
  1. Pneumoperitoneum and moderate amount of intraperitoneal free fluid (water density) is in keeping with bowel perforation. There is a particularly abnormal appearing loop of small bowel that is transversely oriented across the central abdomen. This appears moderately distended, measuring 2.5 cm in maximum dimension and has internal increased density suggestive of blood.
  2. More diffuse small bowel wall thickening in the setting of hypovolemia suggests "shock bowel". Diffuse mesenteric stranding in keeping with mesenteric traumatic injury.
  3. Bulky left adrenal gland suspicious of hemorrhage. 

Case Discussion

Small bowel perforation is a type of hollow viscus injury, which is an uncommon finding in blunt trauma 1. The incidence of small bowel perforation was 0.3% in one study performed by Watts et al 2. Despite recent advances in CT, the false negative rate during CT pan scan is still relatively high. Hence, it is not uncommon for patients with traumatic small bowel perforation to present at a later stage, and hence have a higher morbidity and mortality.

Upon perforation, the accumulation of fluid and air in the peritoneum leads to a gradual onset of symptoms - abdominal pain and tenderness culminating in peritonitis.

CT is the investigation of choice for suspected small bowel perforation. Radiological signs which are seen include free peritoneal fluid, pneumoperitoneum, bowel wall thickening and/or dilatation. Other modalities including plain X-ray (looking for subphrenic air) and Focused Assessment with Sonography in Trauma (FAST) scans have a poor early detection rate of small bowel perforation 1.

Once diagnosed, surgical repair remains the mainstay of small bowel perforation management. 

Complications of small bowel perforation repair include wound infection and dehiscence, abscess formation and other systemic complications such as acute respiratory distress syndrome (ARDS) and sepsis.

Case contributed by A/Prof. Pramit Phal.

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.