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
Investigation of choice for intermittent gastrointestinal obstruction: 
Select and explain. 
A. X-ray, B. USG, C. Enteroclysis, D. Barium meal follow-through
C: Enteroclysis
Answer: C: Enteroclysis 
Explanation: 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