Is a small bowel series safe for patients with diverticulitis and small bowel obstruction (SBO)?

Small Bowel Series is Not Safe for Diverticulitis with SBO

Small bowel series is contraindicated in patients with diverticulitis and small bowel obstruction due to increased risk of perforation, worsening obstruction, and potential for contrast extravasation. 1

Rationale for Contraindication

The American College of Radiology (ACR) Appropriateness Criteria strongly advises against fluoroscopic small bowel follow-through (SBFT) or enteroclysis studies in patients with acute obstruction for several important reasons:

• Patient tolerance issues: Patients with active SBO cannot tolerate the oral contrast administration requirements due to:

  • Inability to ingest large volumes of fluid when bowel is obstructed
  • Increased risk of vomiting and aspiration
  • Exacerbation of abdominal pain and distention 1, 2

• Diagnostic limitations: SBFT has significant limitations in this setting:

  • Cannot reliably diagnose ischemic loops or bowel perforation
  • Limited ability to evaluate for other etiologies of abdominal pain
  • Cannot test bowel distensibility adequately 1

• Safety concerns with diverticulitis: The inflammatory process in diverticulitis creates additional risks:

  • Increased risk of perforation at inflamed diverticular sites
  • Potential for contrast extravasation into peritoneum
  • Worsening of existing inflammation 3

Preferred Diagnostic Approach

CT Scan with IV Contrast

CT scanning is the diagnostic method of choice for patients with suspected SBO, especially with complicating factors like diverticulitis:

• Superior diagnostic accuracy: >90% sensitivity and specificity for detecting SBO 2
• Comprehensive evaluation:
  • Distinguishes between true mechanical obstruction and ileus
  • Identifies the transition point and underlying cause
  • Assesses for complications such as ischemia or strangulation
  • Can detect diverticulitis and related complications simultaneously 1, 2
• Treatment guidance: Findings can guide decisions between operative and non-operative management 2

Contrast Recommendations

• IV contrast is preferred to evaluate bowel wall perfusion and detect potential ischemia 2
• Oral contrast is not necessary and potentially harmful in high-grade obstruction 2

Clinical Implications of Diverticulitis with SBO

The combination of diverticulitis and SBO represents a particularly high-risk scenario:

• Higher operative rates: Patients with concurrent large bowel diverticulitis and SBO are 4.2 times more likely to require surgical intervention than those with diverticulitis alone 3
• Longer hospital stays: Mean increase in length of stay by 3.2 days 3
• Higher rates of open surgery compared to patients with diverticulitis alone 3

Management Considerations

• Early surgical consultation is warranted given the high failure rate of non-operative management in this combined condition 3
• CT findings that suggest need for urgent intervention:
  • Complete obstruction
  • Closed-loop obstruction
  • Signs of ischemia (mesenteric edema, free fluid)
  • Absence of small bowel feces sign 1, 2

Common Pitfalls to Avoid

• Delaying appropriate imaging: Relying on plain radiographs alone can lead to delayed diagnosis
• Attempting small bowel series: This can worsen the clinical condition and delay appropriate treatment
• Missing signs of strangulation: Requires careful interpretation of CT findings and clinical correlation
• Failing to recognize the higher risk profile of combined diverticulitis and SBO compared to either condition alone 2, 3