I cried laughing, such wonderful verse.

And oh dear lord, wash your goddamn anus properly.

My first thought was worms, as described by a kid 'its itchy'. But if it itches after a shit and you only wipe twice, sounds like its a case of dirty-bum-syndrome. Flushable wet wipes and a soapy loofah in the shower should clean things up.

Ingrown hairs would cause an itchy crack but not an itchy star.

Any pain or discomfort when the logs fall out?

And if it doesn't improve with cleanliness, go to the GP and sort out dem worms.