What is the management for boils near rectal opening?

Hello doctor,

I am a 42-year-old man, active in sports. Recently about five days back, while playing football on a concrete floor, I slipped and fell on my lower back (coccyx area) and injured myself. I, however, can carry on my daily activities at slightly slower speed now, and there is slight pain on bending forward. Since two days, a big boil has appeared near my rectal opening. It is dark yellow in color, may be filled with pus, not sure. It is painful whenever I pull in my pelvic or butt muscles. Stools are normal, luckily the boil is above the rectal opening, so no problem in passing stools, but while washing, I can feel the boil and it is painful.

I have pain also while walking. I have three questions.

1. Did the fall I had lead to the boil? Or are these two independent problems?

2. What is the reason for the boil?

3. How to treat it quickly?

Thank you doctor,

Just a quick question. In the prescription, the second and third items are given as zero days. I guess it would also be five days? Another query is if I just leave it like that (without medicines), how long would it take to cure? I have a background of not taking frequent baths. So my problem may be due to my improper hygiene?