hee hee Knowledgeboy!
She cringes, is what she does! A tinkle is fair enough, we drink alot of water, but anything more pressing is a source of embarrassment. It's vile to have to "go to the toilet" inflight, passengers always watching, and the fear of leaving a smell! Although all Stewardesses smell of roses of course.
We've written about this very subject, google us and see what we've been up to, we devoted a whole chapter to it, it's such an important topic, and thank you for bringing it up. There is more to it than the answers you received so far, and we're the ones to provide you with all the answers to all the flying questions you ever want to ask.
Big hugs sweetie, and stay curious!
Love,
Liz & Julie x