Bowel perforation (summary)

Bowel perforation is an acute surgical emergency where there is a release of gastric or intestinal contents into the peritoneal space.

Reference article

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  • epidemiology
    • depends on cause
  • presentation
    • history
      • may depend on the location of the perforation
        • severe and generalised abdominal pain (upper)
        • gradual and localised pain (lower)
      • anorexia, nausea and vomiting
    • examination
      • rigid abdomen and generalised tenderness
      • guarding and rebound
      • bowel sounds range from quiet to absent
  • pathophysiology
    • gastric and duodenal ulceration
    • infection (diverticulitis, appendicitis), ischaemia and cancer
    • blunt and penetrating trauma
    • ingestion of corrosive materials
    • iatrogenic causes (ERCP, colonoscopy, laparotomy, biopsy)
  • investigation
    • an erect plain radiograph is sensitive for small volumes of free gas
    • a supine abdominal radiograph may show signs of free gas
    • CT with IV contrast is the gold standard investigation
      • free gas and fluid within the peritoneal cavity
  • treatment
    • fluid resuscitation and IV antibiotics
    • surgical intervention is often required to close the perforation
      • bowel resection may be required
    • mortality increases the longer surgical treatment is delayed
  • confirm free intraperitoneal gas
  • determine the underlying cause
  • if possible, identify the site of perforation
Plain radiograph
Erect CXR
  • erect CXR
  • very sensitive to even small amounts of gas within the peritoneal cavity
  • seen as a crescent under the diaphragm
Abdominal X-ray
  • performed for other reasons, e.g. to identify bowel obstruction
  • several signs of pneumoperitoneum, e.g. Rigler sign
  • abdominal CT with IV contrast
  • CT is very sensitive for tiny volumes of free gas within the abdomen
  • triangles or bubbles or gas out with the bowel
  • anti dependant - rising to the top of a cavity, e.g. behind the abdominal wall
  • associated fluid within the peritoneal cavity is helpful but non-specific
Finding the cause

CT is also useful to determine the cause of the perforation and is therefore very helpful before surgical intervention.

Where there is more gas than fluid, think upper GI perforation (e.g. duodenal ulcer). Where there is more fluid than gas, lower GI perforation is more likely.

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rID: 31945
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Cases and Figures

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    Case 1: subdiaphragmatic free gas
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    Case 2: football sign of pneumoperitoneum
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    Case 3: duodenal ulcer
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