My cats randomly started fighting.

By on September 5th, 2011

When I got home yesterday I sat down on the couch and after about half an hour I heard growling from behind the couch. My cat was trapped in a plastic bag, me and my mom started freaking out. We moved the couch and he just shot to the other side and freed himself from the plastic. He’s always been super skittish so it was nothing new to me. But then my other cat went after the one in the plastic bag. They were hissing and growling at each other. The cat that was stuck ran into the kitchen and hid on top of the cabinets. He didn’t come down all night so me and my mom tried to get him down, he finally came down in the middle of the night but he was scared. He is potty trained but he went to the bathroom on the floor because he was too scared to go to the bathroom. He hasn’t eaten and drank anything. They are both boys, neutered. We’ve had them both for about 5 years and they’ve been best buds.

What happened to make them so mad. What can I do to help, and how can I make the other one eat, drink, and use the bathroom.