The Mercury and Gemini astronauts used diapers to go to the bathroom
derived from systems developed for long-duration bomber flights.
Apollo astronauts had bags to collect feces and urine and dumped it
over-board daily. Shuttle and ISS has a proper bathroom for zero gee
and sponge baths. On Star Trek they go where no one has gone before.

I have given some thought about a modified mechanical counter-pressure
suit that has a MEMS (micro-electro-mechanical system) based jumpsuit
- that cleans, hydrates, oils and otherwise takes care of all bodily
functions - including sweat and hair growth.

http://docs.google.com/viewer?a=v&q=...NWG-0KM0zoqaNQ

These suits would be built for extremely long duration - perhaps
several years - minimizing the mass of transporting astronauts between
worlds.