This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammatory bowel disease, Subject name: Surgery
[{'content': "True statement regarding anorectal Crohn's disease: \nSelect and explain. \nA. Ulceration, fistula is common, B. Fistulas are painless and indurated, C. Non-cutting setons are used in management, D. All of the above", 'role': 'user'}, {'content': "Answer: D \nExplanation: CROHN'S DISEASE OF THE ANORECTUM Typically presents in three ways: Ulceration (MC), fistula and stricture. Fistulas tend to be chronic, indurated, and cyanotic and are often painless. Abscesses need to be drained and fistula tracts require chronic drainage with non-cutting setons. Once the perianal sepsis is controlled, infliximab treatment is initiated. After two or three infliximab infusions, the setons are removed to permit closure of the fistulas.", 'role': 'assistant'}]