Are they on the entry to your anus, or on your buttox ?
These could be 'piles', if actually at the entry of you anus, which can be treated with 'Anusol' .. ask your Chemist. .... or if you are really concerend, go and see your Doctor, Piles are common, and easily treated.
Good luck and get speak soon.
I'll re-post you to another Forum - so you get more advise ..

Ginger