Perianal Abscess

Derek Moore is a 33-year-old male presenting with painful perianal swelling. About four days ago, I noticed some discomfort near my back passage when I was sitting at my desk at work. I thought it might be a hemorrhoid or something. But over the next couple of days, a definite lump appeared just to the left of my anus. Your task is to take a focused history from this patient.