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
All of the following are known complications of ulcerative colitis except : 
Select and explain. 
A. Stricture, B. Perforation, C. Toxic megacolon, D. Carcinoma
A: Stricture
Answer: A: Stricture 
Explanation: • Inflammation is purely mucosal in ulcerative colitis, strictures are highly uncommon. Any stricture diagnosed in a patient with ulcerative colitis is presumed to be malignant until proven otherwise.