NASA's tutorial video on the operation of a space toilet is charmingly squeamish — it's vacuum operated and not one person in this whole video makes a "this sucks shit" joke. OTOH, they do mention the in-toilet camera (used to guide your aim so that expended food is aligned over the suction hole) and the recycling of waste-water for drinking water.
(Thanks, Joe V!)
Update: Joe sez, "Having attended the International Space University (Space Camp for adults!), we got a number of technical briefings on space shuttle equipment. Not only does the Shuttle suck shit, but as the waste is being sucked into the holding tank, a device was needed as it won't stay there in zero gravity. The solution? The shit literally hits a fan which spatters it all over the sides of the holding tank, where it stays put (shit is sticky). So, boo for no 'shit hits the fan' jokes too!"