 As a running gag, bathrooms are never shown on Enterprise  schematics. This joke is referenced in  _Star Trek: First Contact (1996)_ (qv) when Zefram Cochrane asks  Geordi, "...dont you people from the 24th Century ever pee?" Also,  in an interview during the mid 70s on  _"The Tomorrow Show" (1973)_ (qv) with Tom Snider (qv),  James Doohan (qv) stated that bathrooms werent needed in the  future because "thats what phasers are for".