Did he throw up after he ate the beans? I had the same problem after my Priss ate some Chick-fil-A. She threw up then wouldn't eat for several days, not even wet food and became very lethargic and lost weight. They don't eat because they think they will throw up. We went to the vet and she gave her fluids gave us some anti nausea medicine and some medicated wet food that we had to force feed her with a syringe. Once she realized she could eat without throwing up (thanks to the medicine) it took a few days, but she came around. Good luck to you, it appears that you have a similar situation.