This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Radiology
[{'content': 'A 30 year male presents with acute abdomen. What is the diagnosis based on the CT abdomen given below? \nSelect and explain. \nA. Pneumoperitoneum, B. Toxic megacolon, C. Perforation peritonitis, D. Bowel obstruction', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D. Bowel obstructionThe CT abdomen shows multiple dilated small intestinal loops, seen in intestinal obstruction. The black shadow anteriorly is of gas in Transverse colon.A bowel larger than 3cm in diameter is associated with small bowel obstructionThe upper limit of normal diameter of the bowel is generally accepted as 3cm for the small bowel, 6cm for the colon and 9cm for the caecum (3/6/9 rule).', 'role': 'assistant'}]