This does seem like a comedy thread to me, but I will go ahead and approve this idea anyway. I'm all for realism, and I always get tired of that you can run for 10000 hours in a game and never ever have to shit and pee and so on. In normal FPS you don't eat or drink either, and Facepunch have taken that step, so why not go all the way?
Some other levels of realism that could be added; sneezes (these happen on random, and shake your view wildly, making it devastating at some point of your Rust journey) coughing (these also shake your view, but milder, but also longer. These could happen while going through radiated areas).
wow, sneezes idea is epic! i love it!