This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': "Wireless capsule endoscopy is done to visualize which of the following condition? \nSelect and explain. \nA. Esophageal varices, B. Gastric carcinoma, C. Crohn's disease, D. Ulcerative colitis", 'role': 'user'}, {'content': "Answer: C \nExplanation: Crohn's disease Wireless capsule endoscopy (WCE) allows direct visualization of the entire small-bowel mucosa. The diagnostic yield of detecting lesions suggestive of active CD is higher with WCE than CT enterography or small-bowel series. WCE cannot be used in the setting of a small-bowel stricture. Capsule retention occurs in <1 % of patients with suspected CD, but retention rates of 4--6% are seen in patients with established CD.", 'role': 'assistant'}]