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
An appendicular fistula is least likely to heal if - 
Select and explain. 
A. The stump was sutured with vicryl, B. There is stenosis/narrowing of the sigmoid colon, C. Superadded infection, D. None
B: There is stenosis/narrowing of the sigmoid colon
Answer: B: There is stenosis/narrowing of the sigmoid colon 
Explanation: Unrelieved obstruction of tube distal to fistula is a cause of persistence of fistula.