need advice on flying with a cat

I am moving across the country and will take my 5-year-old cat on
American Airlines.  He will be traveling in the cargo hold for a 5.5
hour flight (assuming no delays).  Should I feed and try to water him
right before the trip?  Should I leave some food pellets inside the
cage for him to munch on?  Should I worry about bathroom "accidents"?
Any advice from experienced travelers will be greatly appreciated!