CT and MRI features of bowel obstruction
The major imaging finding is upstream dilation and downstream collapse of bowel with respect to the site of obstruction (i.e., the transition zone).
Other findings may include focal bowel wall thickening; mass; luminal filling defect; luminal narrowing or angulation, tethering, or beaking of bowel at the transition zone; a mixture of particulate material and fluid within upstream dilated small bowel, mimicking the appearance of feces (“small bowel feces” sign); air-fluid levels within upstream dilated small bowel; and gradual dilution of oral contrast material when passing from proximal to distal in dilated bowel upstream to the site of obstruction.
Associated findings of bowel ischemia/infarction described below may also be present.
