The very entertaining Mike Massimino, a former NASA astronaut who helped fix the Hubble telescope in orbit, was on The Daily Show and explained in detail to host Kal Penn how astronauts poop while traveling in space. It requires a lot of training, including simulations and a closed-circuit camera and TV.
And even with all this training, once in space, you may need to take a moon walk.
Also discussed are Massimino's path to become an astronaut, UFOs/UAPs, and a very moving description of the view of Earth from space.
I've actually read Massimino's new book, Moonshot, and it's an insightful, useful (and funny) account of the life lessons about perseverance and teamwork he's learned from becoming and being an astronaut.