If I had a sore bum I wouldn't want to eat either, poor guy. What does the vet say about how long he can go without eating? I know for cats it's dangerous and I've had to syringe feed my cat a few times when she was off her food.
It is dire out there. I'm thinking I need to pull back from forums for a while and do what Kaily said, "No internet or news so you just know what you know in your own life." I gave up news a long time ago, but I can't escape it (the economic and psychological trauma) on forums.