Interesting (maybe) but irrelevant (mostly): if cabin air pressure is about a third of what it is on the ground, personal compressed gas is a much higher volume on the air. Pilots and crew eat mostly non-gas producing foods before a flight.

Think of what could have happened if you'd let loose while up there, and I don't think the results would have been evident on the 'black box'... or would it be the 'brown box'? Anyway, an operational sphincter is a good thing.