If you are using the bathroom and someone walks in, do you stop peeing? For me, I stop. I try to make as little noise as possible because people can’t know that I, a human being, pees.
In school we are practically trained to not fart or burp in public because if you do, people will laugh at you. But why? Everyone burps, everyone farts, everyone pees etc. What is so bad about letting others know that you have bodily functions that everyone else has? I did some research (a quick Google search) and the first things that pop up are about how women hide their bodily functions and men don’t (at least not nearly as much as women).
I grew up in a home with two brothers, they burped and farted all the time in front of each other, so I did the same. As long as I was at home with my family, I wouldn’t hide any bodily functions. Later on I learned to hide them. I went to (female) friends’ houses who had ‘rules’ where if you need to fart, you need to go to the bathroom and fart, then you can come back. My current roommate asked if we should have any rules about burping and farting. Why do we feel the need to limit bodily functions? Yes sometimes burping and farting don’t have the best smell but it is a necessary bodily function.
From a young age, we are taught that burping and farting are un-ladylike. We are told to make ourselves smaller and to not make noises. But men are allowed to do whatever because ‘boys will be boys’ and whatnot. Sexism is rooted in so many aspects of women’s lives where many women may not realize why they do not like being open with their bodily functions.
Unruly Bodies 
I cannot pee when I think someone is listening. Even when I had surgery and needed help in the bathroom, my mom had to run the sink water so the tinkle noise wasn’t heard. I always thought my shy bladder was linked to anxiety, but I never thought about it much deeper than that. Even in our Unruly Bodies classroom I am painfully aware of my squeaky chair because it sounds like a fart and I don’t want people to think I’M the one who farted… You raise a good question about why people(and me) even have such anxieties and why we are conditioned to hide normal bodily functions.
i’ve never thought about how hiding bodily functions was rooted in gender norms and stereotypes. back when i was just starting my period, i would always wait until everyone else left the bathroom so they wouldn’t hear the sound of me tearing open my pad. just like you said, so many people have these bodily functions, but for some reason we are taught to be ashamed of them or embarrassed by them occurring. how is it that so many of the debilitating norms and stereotypes are placed on minority groups? is it that the norms make us a minority, or the treatment of the minorities were further justified by the norms?