Is my ball sick? Please help :(

[RockNRollProcelain]

My ball python has been having what looks like diarrhea and leaving marks of it on the sides of his cage. This has happened twice, both times it happened a few days after being fed. He is eating regularly and seems to be healthy other then the diarrhea and the fact that he hasn't shed in 2 months. Should I be concerned? Should I take him to a vet?

I don't know what's wrong with him, but if he's not having healthy poops, he needs to go see the vet. Whenever there is a symptom like that, any animal should be brought to the vet, whether or not they are a snake. So call up your vet, schedule that appointment, and let us know how it goes!