Hi, i have a sore where my butt cheeck begin, it is painfull when i sit or lay on my back, it doesnt hurt when i stand up or walk, i can feel its getting bigger, and it is very warm on and around it, i had this once before, it got so painful that i couldnt even walk, and once i opened it, what a relief, pain completely gone, but there was alot off greenish yellow bloody puss coming out of it, alot, i drained it for about 3 days and it healed completely, now i feel it coming on again, what causes this and how can i prevent it??? I keep my body clean and always put some savlon in my bath water, what can cause this, it is really uncomfortable and painfull....