I only wanted to mention poopy suits because I like the name. They are actually anti-exposure suits that aircrews wear when they are flying over cold water areas (such as the North Atlantic), so in case your jet goes bad and you have to eject, you'll be able to survive in the cold water an extra half hour or so, waiting on someone to find you and pluck you out. They are somewhat similar to a diver's wetsuit, made out of rubber, and you put them on over long johns. You then put your flight suit, survival vest and harness. When you're all suited up, it looks like you've gained 100 pounds, but you'll end up losing at least 5 per flight by sweating in those things...
One thing you learn while wearing a poopy suit is bladder control. I had to wear one while flying a jet across the Atlantic, and there was no way I would have been able to get to the part I needed to (through all the zippers and flaps) in order to relieve myself. Even if I had, it would have been nearly impossible to use the "piddle pack" (kind of a little plastic bag with a sponge in it, with a long narrow neck) since there was no room to move in the cockpit, strapped to the seat with the control stick stuck between your legs, wearing that semi-stiff poopy suit. Try to picture it. Needless to say, they weren't my favorite things to wear.
I guess it got it's nickname from those guys who couldn't wait...