Stack of Coins Sign in Small Intestine
The "stack of coins" appearance on abdominal X-ray indicates small bowel obstruction (SBO) and requires immediate CT imaging to determine the cause, severity, and need for urgent surgical intervention 1.
What This Finding Means
The "stack of coins" sign represents dilated small bowel loops with visible valvulae conniventes (mucosal folds) that appear as stacked coins on plain radiography. This is a classic radiographic finding of small bowel obstruction.
Immediate Diagnostic Approach
Plain radiography alone is insufficient and potentially misleading. While abdominal X-rays can detect SBO with 60-70% sensitivity, they fail to identify the cause, location, or complications in 20-40% of cases 1. CT abdomen/pelvis is the primary diagnostic tool of choice because it provides critical information that directly impacts management 1:
- Identifies the underlying cause (adhesions, malignancy, hernia, bezoar, volvulus)
- Determines obstruction severity (complete vs. partial)
- Detects life-threatening complications requiring emergency surgery:
- Closed-loop obstruction
- Bowel ischemia (mesenteric edema, free fluid)
- Strangulation
- Perforation
Modern multidetector CT has 87% sensitivity and 90% specificity for identifying the etiology of SBO 1.
Critical Clinical Assessment
While obtaining CT, assess for emergency surgical indications 1:
- Signs of peritonitis (rebound, guarding, rigidity)
- Hemodynamic instability (hypotension, tachycardia)
- Fever with leukocytosis and left shift
- Elevated lactate (suggests ischemia, though normal values don't exclude it)
- Diffuse severe abdominal pain
Examine specifically for external hernias (groin, umbilical, incisional) as a reversible cause 1.
Management Algorithm
If Emergency Surgical Signs Present:
- Immediate surgical consultation
- NPO, IV fluid resuscitation
- Nasogastric decompression if significant distension/vomiting
- Broad-spectrum antibiotics if peritonitis suspected
- Emergency laparotomy
If No Emergency Signs:
CT findings determine the pathway 1:
For high-grade/complete obstruction without ischemia:
- Initial non-operative trial may be attempted in select stable patients
- Water-soluble contrast study can predict success (contrast reaching colon within 24 hours = 96% sensitivity for resolution with conservative management) 1
- Surgery if no improvement within 24-48 hours
For partial obstruction:
- Non-operative management typically successful
- Serial examinations to monitor for deterioration
Common Etiologies to Consider
In patients WITHOUT prior abdominal surgery (virgin abdomen), the differential is broader 1:
- Adhesions (63% - can occur without prior surgery)
- Malignancy (11%)
- Internal hernia (4%)
- Bezoar/foreign body (5%)
- Volvulus (4%)
- Meckel's diverticulum
- Gallstone ileus
In patients WITH prior surgery:
- Adhesions are overwhelmingly most common (>75%)
Critical Pitfalls to Avoid
- Don't rely on plain films alone - they miss the cause and complications in most cases 2
- Don't delay CT in stable patients - it changes management more than any other test 2
- Don't assume virgin abdomen = no adhesions - adhesions cause 63% of SBO even without prior surgery 1
- Don't miss strangulation - normal lactate doesn't exclude ischemia 1
- Serial examinations are essential - single X-ray cannot differentiate SBO from ileus in postoperative patients 2
Disposition
All patients with confirmed SBO require surgical service evaluation and admission 3. The surgeon determines operative vs. non-operative approach based on CT findings, clinical trajectory, and response to initial management.