Potpourri-Xrays

Bowel Obstruction

Bowel Obstructions

SBO:

- Distended small bowels >3cm

Supine view

• Distended small bowel (>3 cm); (“stack-of-coins”)
• Relative paucity of air and feces in colon

Upright view

• Differential air/fluid levels (“step-ladder”)
• Broad air/fluid levels (“tortoise-shell”)
• “String-of-pearls” sign

Reasons for Nondiagnostic Xrays in SBO

• Partial or early SBO
• Fluid-filled bowel
• Proximal obstruction

LBO >5cm dilated

Sigmoid volvulus

• Coffee bean—a doubled-back and dilated bowel segment
• Extends from left lower quadrant to right upper quadrant
• Proximal large bowel dilated

Cecal volvulus

• Single dilated segment (kidney-shaped) in mid or upper abdomen
• Distal large bowel collapsed, unless concomitant colonic ileus
• Small bowel often dilated (effectively obstructed at terminal ileum)

Large bowel obstruction—distal

• Diffuse distention of large bowel and often small bowel
• Cecum disproportionately distended (75% of cases)
• Rectum not distended

Ileus—pseudo-obstruction

• Diffuse distention of colon and often small bowel
• Rectum distended on CT or prone rectal view (air filled)

Toxic megacolon

• Distended colon with focal bowel wall edema (nodularity)