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: Surgery
Investigation for acute abdomen includes 
Select and explain. 
A. USG, B. Multidetector CT, C. Contrast enhanced CT, D. X-ray
A: USG
Answer: A: USG 
Explanation: .Gram -ve septicaemia is common in acute abdomen like peritonitis, abscess, urinary infections, biliary infections, postoperative sepsis. It is commonly seen in malnutrition, old age, diabetics, immunosuppressed people. Diabetic acute abdomen -Patient with diabetes mellitus may present as acute abdomen. Free fluid in the flank may not be present. Patient may be ketotic also.the investigation of choice in a case of acute abdomen is ultrasound. ref:SRB&;s manual of surgery,ed 3,pg no 502