How An I Get Rid Of Boil In My Buttocks ?

i have a boil in my right back from past one year. location is exactly at the sitting condition. i dont have pain and its not hard. once in a week there will be discharge of mucous and blood when the boil opens (i ll squeeze it to open) and rest will be fine until a week or 10days , again the boil returns. i am 31yrs of age ,male. no diabetes , slight cholesterol. otherwise healthy. i used to smoke, but left from one year, drink occassionally (once in a week) please advice