Layer 1- Waterproof mattress pad + fitted sheet
Layer 2- Waterproof mattress pad + fitted sheet
(Yes, twice. Then you can pull the yucky layer away and be fresh and ready for more. Works well for potty accidents, too.)
For the floor:
Layer 1- Vinyl tablecloth
For any other room:
Repeat layers for floor, but apply to seating area (ie: couch) as well. Make a plastic lined, absorbent sicko zone.
And don't forget a few things for comfort after any stomach event:
Tissues for cleanup
A drink of water
Oyster crackers- like soda crackers, but adorable and bite size
And a drink of what we call "Yellow Juice" to sneak in some fruits & veggies that are easy to digest. It's also good mixed with a little lemon/lime soda.