Hi doctor. Iam a boy aged 17. In around 1 month, im having a pimple inside my butt.  Im not sure whether its a pimple. This is located on top of my butt  and not inside anal hole, which cannot be seen from outside. It was only painful when i rub my butt while sitting. And today when i scatched it, pain increased and blood came out. Please explain my condition in detail and please tell me the solution in detail.