I mean this has also been a problem for fighter pilots as well. The "piddle packs" for F-16 pilots are implicared at least one crash due to the complexity of using them.
Forget about pee, I always wondered about fighter pilots in one of those long, multi-hour flights, what happens if they really need to go number 2? I suppose they self-select as people without this kind of problems, but it can happen to anyone really.
I suppose in an emergency they just shit their pants, but I wonder what the ground crew says when they touch down.
Honestly this isn't something people select for at all--by the time you've made it through that many rounds of selection you aren't going to let GI issues keep you from the finish. I've heard of some creative solutions to the problem involving safing the ejection seat and getting out of your gear, but I don't really believe any of them. If you think it's a significant risk, you basically have two options: talk to the squadron flight surgeon and get medically grounded, or wear a diaper. Almost everyone is too proud to do either of those things, so a number of pilots have call signs related to shitting themselves in flight. Yes, everyone will make fun of you after the fact--if you're a decent person, you'll at least clean out the cockpit yourself.
That's one option, although for longer missions your preparation generally needs to start the night before and I wouldn't recommend flying on an empty stomach (unless it works for you, but it makes most people more susceptible to airsickness). There isn't one consistent method that works for everyone--I think the book Sled Driver has a section where they talk about physiological preparation for SR-71 flights, and the only consistent habit the crew had was NOT eating the "traditional," low-residue steak-and-eggs breakfast.
Good news for gassy food lovers is the cabin pressure changes make everyone fart, there's no one else in the cockpit to hear or smell you, and even if there was it'd be loud and they'd be wearing an oxygen mask. Little victories.
Imodium also does wonders for slowing things down and avoiding bowel movements, provided you use it carefully and infrequently such that you don't totally mess up your normal gut functioning.
The context is piloting a fighter aircraft in a multi-hour combat mission though. I think missing meal might matter for mission critical, uh, missions.
I'm not talking doing menial work while skipping lunch.
I didn't know that! But I do know that crews got eggs before flights. Nobody else did.
When RAF pilots went to the Soviet Union to help the Soviets, when the first frost came the pilots were horrified when the women brought out big vats of fat and ladled it out. But after flying in those cold temperatures, they realized the fat was just the thing to keep them warm!
Doing barrel roll, twist and speed up - radio to airliner „see buddy can you do that?”
Airliner „wait a moment” - some time passes nothing happens - airliner „hey buddy you seen that?” - f16 „what? Nothing happened” - airliner „I went to toilet on the back, took dump, made myself a coffee and strolled back to cockpit”.
[1] (NSFW lyrics!) https://www.youtube.com/watch?v=jd9_RffdmBA