Unfortunately when I called my vet they couldn't get him until later. (About an hour and a half). But I just checked him again and it looks completely normal and he seems fine. Thank you for your input and I will let you know what happens at the vet! :)
My cat is four years old, and something weird happened today that, even though I have an appointment for him at seven tonight, still has my stomach in knots. He hasn't been pooping much lately, I think due to the change of food, but he acted completely normal. Earlier his butt was very swollen...