Hey, for the last 3 weeks or so I've had this medium sized blister on the top part of my rear end crack. At first I thought it was just a blister but I'm not sure now. When I pop it whiteish puss and blood comes out of it. Is it just a normal type blister? Should I try just putting some bactine and a bandaid on it and see if it helps? Any information as to what you think it could be would help a great deal. If it helps, it came around after I spent a few days sitting down for 12+hours on end at a desk.