I am new to flying and I have been wondering one thing, but tooo embarrassed to ask pilots in person. What do you do when nature calls when at you are at 10,000 feet in a Cessna 172? Especially when that bean burrito is not sitting well (I will not name restaurants

. I have not had this happen yet, but want to know what the pros do. Oh and I already know the pucker factor and praying, so any other situations (mishaps). Don't be shy.
Newbie pilot