Q: I have an infection just above the buttocks, near the tail bone. It swells once in a month when pus and blood comes out of it. Then it goes dormant. Its been there for nearly a year and half now. Doctor said it is pilonidal sinus and needs surgery. I haven't gone for a surgery due to personal reasons. Can this be dangerous? Can it turn malignant? How soon should I go for a surgery? How long will the recovery take?

A:From your description, the most likely condition is pilonidal sinus. A pilonidal sinus is a track/blind tunnel that burrows into the skin, and is caused by the pressure of air. It needs surgery. The other possible diagnosis is a fistula in ano. A fistula is a tunnel that starts in the skin and communicates with the last part of the intestines (the anal canal). Confirm with your doctor that he has ruled out a fistula. This needs a different kind of surgery. These conditions do not turn malignant. You should consider surgery at your earliest convenience.