On a plain abdominal radiograph, which feature distinguishes small bowel obstruction from large bowel obstruction?
Answer and explanation
Correct answer: C. Central dilated loops over 3 cm with valvulae conniventes across the lumen
- Step 1: The small bowel is central with folds that run across the lumen, and the large bowel is peripheral with haustra. Step 2. Small bowel dilatation is over 3 cm, large bowel over 6 cm and caecum over 9 cm. Answer: Central dilated loops over 3 cm with valvulae conniventes across the lumen. Why not the others: The peripheral loops with haustral markings and a diameter of 6 cm describe large bowel. Gas confined to the stomach suggests gastric outlet issues. Air under the diaphragm indicates perforation.
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