might well be the onset of piles you will notice blood if this is the case, try and eat lots of fibre bran flakes etc and if it is piles then you can get creams and suppostries from the chemist,but if it persists go see your gp and dont be embarrassed.
I know this feeling so well,fischer's are so damn painful,when they keep coming back and back,omg,cant believe i just said that,but make sure you drink plenty,i don't and thats my problem!!!
If it is an anal fissure, the pain will be intense. Having been through the whole gamut of anal problems due to Crohn's disease, I would recommend a visit to the doctors if the pains persist.