This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
Most common cause of anorectal abscess is 
Select and explain. 
A. Inflammation of anal gland, B. Folliculities, C. Inflammation of rectal mucosa, D. Recturn
A: Inflammation of anal gland
Answer: A: Inflammation of anal gland 
Explanation: Anorectal abscess # Usually produces a painful, throbbing swelling in the anal region. The patient often has swinging pyrexia # Subdivided according to anatomical site into perianal, ischiorectal, submucous and pelvirectal # Underlying conditions include fistula-in-ano (most common), Crohn's disesase, diabetes, immunosuppression # Treatment is drainage of pus in first instance, together with appropriate antibiotics # Always look for a potential underlying problem Ref: Bailey & Love&;s Sho Practice of Surgery,E25,Page-1262