This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intestinal obstruction, Subject name: Surgery
[{'content': 'Investigation of choice for intermittent gastrointestinal obstruction: \nSelect and explain. \nA. X-ray, B. USG, C. Enteroclysis, D. Barium meal follow-through', 'role': 'user'}, {'content': 'Answer: C \nExplanation: SBO IOC for Dx: X-ray Abdomen ERECT | AIR-FLUID LEVELS SUPINE | SITE OF OBSTRUCTION supine > Erect Gold standard: Diagnostic unceainty High grade obstruction Etiology Strangulation IOC for Dx of low grade intermittent SBO: Enteroclysis', 'role': 'assistant'}]