What Does A Boil On Buttocks Indicate?

Hello I have a boil which is located in the uppermost part of the buttocks, very close to the crease. It s covered with hair and I m not able to see the boil. But i pick the hair and i can see a red boil. And then again it gets surrounded with hair and some kind of black material like cotton( not sure what it is exactly). I have also found tiny yellow fluids on my vests in the morning. What kind of ointments or tablets will i be needing to cure this? Is it serious?If i have to consult a doctor what kind of doctor do I have to see? Any changes in diet or anything you recommend me to follow Thanks in advance