I have an open sore on my right buttocks

I've had this open sore on my right buttocks for the last 4 1/2 years and it drains a light green pus pretty constantly.  It can close up or "heal" but it expands and becomes painful until it breaks again.  I went to a general surgeon 4 years ago but was turned off by his approach, referring to "fillet me open."  What he did say was that it as a "fistula-in-ano."  Since I never went through with getting this taken care of because of the way this Doc smelled (wreaked of cigarette smoke) and his "fillet" comment.  What more can I know about the procedure and what can I do to eliminate the cause of getting them in the future.   thanks!