Could be razor burn, irritated or full anals, worms or something else itching or hurting his rectal area. Let the vet check him out and take a stool sample & a video of him doing it to the vet with you.
__________________  Jeanie and Tibbe One must do the best one can. You may get some marks for a very imperfect answer: you will certainly get none for leaving the question alone. C. S. Lewis |