Any kind of recurring pain is not normal. You could have an anal fissure which is really a cut from possible straining or some inflammation in your cuff, assuming you still have one. It is worth getting checked out as they can prescribe rectal creams and or meds that should help you if you have either of these.

Depending on how long it lasts it could be you just need to use something like Calmoseptine Ointment, Desitin, or something else for a red irritated rear end. You could have eaten something that irritates you. How long have you had your j-pouch? If it doesn't seem right then you should see your GI. I had problems and assumed they were part of the healing process and waited until my first annual check up to have things looked into. I should have gone in to see the doctor months before I did. So when in doubt my advice is to go!