Pilonidal Cyst / Abscesses
Sounds painful, and I agree with Crazywillie - get it checked out!
OK wrong name, here is the correct one
A pilonidal sinus
Wrong spelling or not I have told you what it is, go and get it fixed.
Crazywillie;
I've never heard of "Anal Pialitis" - and that term only has one result on Google - this post. Are you sure you're spelling it correctly?
Zomghax;
Go to the doctor. Anything like what you describe could lead to a bad infection.
Morgannon
You have Anal Pialitis which is caused by an ingrown hair,, what happens is that the ingrown hair becomes infected, what you need to do is go to the doctors, if you catch it early you may be able to avoid a very very painful opreation, many Anal Pialitis ops involve taking a piece of flesh the size of a large fist, this hole is located in the crack of you backside directly under the tailbone at the base of your spine.
Get an exam. I've read something a long time ago and I'm not sure I remember it accurately. Get it checked out because I believe you can end up with infections.