One would assume, despite never being shown or mentioned.. Except for in Star Trek 8 first contact, when Zefram Cochrane says.... "I gotta take a leak." "Leak? I'm not detecting any leak." "Don't you people from the twenty-fourth century ever pee?"- Cochrane and La Forge
Which is a nod to the fact we never see a 24th Century Toilet.
While we never see inside them on the show, there were doors on the sets labeled "Head" (naval terminology for bathroom) most notably on the bridge of the Enterprise-D.
Also, during the brig scene in Star Trek 5, the seat Kirk sits on, is labeled with signage suggesting it is a toilet
I think there might be vaporising toilets
Are there bathrooms where?
There were also two bathroom scenes. One was in the episode where Dr. Polaski was infected with a virus that caused rapid aging. They went to the bathroom in her quarters, and obtained a strand of her hair (with a folicle) from a drawer in her bathroom. The other scene was in a dream sequence in the beginning of First Contact. Picard went to the bathroom, a sink slid out, and he splashed water on his face.
That, plus all the mentions in DS9 of "waste extraction" says there are plenty of bathrooms.
There were more than two bathroom scenes. Jonathan Archer had a mishap when the gravity went out while he was taking a shower. B'Elanna Torres was shown once using a sonic shower. Deanna Troi was shown to have a bathtub in 'Genesis.' Mirror Kira Nerys also had a large bathtub, albeit in the middle of her living room. The interior of Kathryn Janeway's bathroom was shown in 'Live Fast and Prosper.'
No offense, but do you really want to see people going to the bathroom? Episodes are only 40-something minutes long and I don't want to waste them watching people taking care of their "personal business" like the episode of BSG where we watch Admiral Adama shave for ten minutes. Nor do I want to listen to Charles Tucker describe how human poop on a starship gets recycled into a pair of boots. Or how everyone's urine gets recycled into drinking water. On the Apollo missions they were smart enough to dump the unrine overboard!
Bathrooms for some reason are a very touchy subject in Star Trek. Franz Joseph Schnaubelt's deck plans in the Star Trek Star Fleet Technical Manual depicted them, but some of the canonicity of this work (the parts that were not shown on the bridge viewscreens in Star Trek: The Motion Picture, et seq.) have been called into question. Kind of like the scene in Pleasantville, where Reese Witherspoon's character enters the bathroom stall to find a featureless floor, rather than a toilet. ProfessorTrek 10:44, July 29, 2011 (UTC)