Do the x-ray findings suggest constipation with overflow?

Interpreting X-ray Findings for Constipation with Overflow

X-ray findings showing significant stool burden, particularly in the proximal colon with liquid stool distally, are consistent with constipation with overflow diarrhea.

Radiographic Features of Constipation with Overflow

• Abdominal x-rays can confirm the presence of a large mass of dry, hard stool in the rectum or proximal colon 1
• Fecal impaction is evidenced by significant stool retention on x-ray, with 52.1% of older adults showing predominant loading in the ascending colon 2
• When fecal impaction occurs, watery stool from higher in the bowel may leak around the impaction (overflow), creating paradoxical diarrhea 3
• Key radiographic findings include:
  • Moderate to large stool burden visible on plain films 4
  • Dilated bowel loops proximal to the impaction 5
  • Absence of air-fluid levels of differential height (which would suggest obstruction) 6

Clinical Correlation with X-ray Findings

• Rule out impaction is especially important when diarrhea accompanies constipation, as this often represents overflow around an impaction 3
• In patients with suspected constipation with overflow, physical examination findings may not detect all impactions, particularly those in the proximal rectum or sigmoid colon 3, 1
• Objective parameters on abdominal x-ray that suggest significant constipation include:
  • Total stool length greater than 33.4 cm
  • Cecal diameter greater than 3.7 cm
  • Stool length in the rectum greater than 5.9 cm 7

Management Implications

• When x-ray confirms fecal impaction with overflow:
  • Disimpaction should be performed (manual fragmentation and extraction) after appropriate analgesia/anxiolytic administration 3, 1
  • Follow with glycerine suppository or mineral oil retention enema 3
  • Implement a maintenance bowel regimen to prevent recurrence 3, 1
• For patients with cancer or receiving palliative care, constipation management should be particularly aggressive:
  • Discontinue any non-essential constipating medications 3
  • Add and titrate bisacodyl 10-15 mg daily-TID with a goal of one non-forced bowel movement every 1-2 days 3

Limitations and Considerations

• Plain abdominal radiography has limitations in diagnosing constipation:
  • Sensitivity of 74-84% and specificity of 50-72% for detecting significant stool burden 5
  • 28% of patients with moderate or greater stool burden on x-ray may have diagnoses other than constipation 4
• Fecal loading on radiography does not preclude more serious diagnoses:
  • Always rule out obstruction with physical exam and abdominal x-ray before proceeding with disimpaction 5, 1
  • Look for signs of complete intestinal obstruction such as air-fluid levels of differential height 6

Conclusion

The x-ray findings of significant stool burden with evidence of liquid stool distally are highly consistent with constipation with overflow. Management should focus on disimpaction followed by a maintenance bowel regimen to prevent recurrence 3, 1.