The second one. I think of the phrase “go to the bathroom” as having practically completed the transition from having its literal meaning to being a euphamism for urinating/defecating, with sometimes droll results (eg “going to the bathroom in the hallway” above).
I think of a “restroom” as a public facility, while a “bathroom” is a room in someone’s house (which may or may not contain an actual bath. I might say “This house has one bathroom and one half-bathroom,” but I’d never say, “Excuse me, I’m going to go to the half-bathroom”).
In answer to the OP’s question: “Going to the bathroom” could either mean going to the room in question, or performing the activity one performs in that room, depending on the context. E.g. “He went to the bathroom to wash his face” vs. “He went to the bathroom in his pants.”
What’s with all the public announcements (outside of Alienhand’s family traditions)?
“Excuse me for a moment” will usually suffice.
Interesting question - I never thought of it before. Oddly enough, I think that when I’m at home, I’ll think “I have to go to the bathroom” means, “I have to go urinate/deficate”. When I’m at a restaurant, however, it means, “I want to get up from the table and walk over there to the bathrooms,” because I hate sitting in restaurants, and it’s more about walking around than biological needs.
I’m not sure how well “going to the bathroom” really works outside the USA. In many New Zealand houses, the toilet is not in the bathroom but in it’s own little room. Visiting Americans can get embarrassed and confused if they ask “where’s the bathroom?” and then not find what they were looking for. We would ask “where’s the toilet?” and in public, signs say “Toilets” not “Restrooms” or “Washrooms” as they say in Canada. I guess we’re a little more blunt about bodily functions.
I don’t use this phrase, it is an Americanism that is not always understood in the UK.
If someone else says it I assume they are going to urinate.
What, no one ever expects those, either? 
Neither - ladies never announce or think about the need to relieve themselves! Well, that was what I was taught anyway. When I say it, it means, “I’ve got to pee,” “I need a tissue” or I need to do something else like pick my teeth or put on lipstick.
Since old habits die hard, it would never mean, “I’ve got to poop.” If I do announce that I’m on my way to the bathroom, I’ll usually say a simple “Excuse me,” or “I need to visit the ladies’.” My mom hated when we actually said the word bathroom. She thought it was gauche. I think that’s somewhat silly since you’re referring to a room, not necessarily the act. Regardless of how I put it, generally I’m referring to the notion of actually doing it, not getting up to do it.
So, then, how exactly do you ladies manage to not make a mess of your panties? :dubious:
Like I’m going to explain.
cute story
At my workplace, I usually get the cashier supervisor’s attention by hitting a magic button. Said cashier supervisor is then expected to come over close enough that I can tell him or her what’s needed. On one occasion, what I needed was a roll of reciept tape, and what I got was a co-worker prepared to send me on a break. I told the co-worker as much, and he got reciept tape before I left for the break.
I usually just say “I have to race like a pisshorse.”
I don’t know how they did it - my mom and sister seem to have been descended from camels. They could hold it like no one I’ve ever met. I can only recall and handfull of times that I’ve seen either of them stop in the ladies’ in a public establishment. On the other hand, I have a bladder about the size of a grape and am careful to scope out any available bathroom in the area.
Personally I say “I’m going for a shit”,then when I’m actually in action Itry to make the farts as loud as possible and make loud grunting and moaning sounds so as to entertain anyone within earshot.
Afterwards I like to give everyone an indepth description on quantity,consistancy,colour and aroma and if at all possible I like to leave a few samples smeared around the pan so that they can verify my account.
I find that leaving piss and a couple of pubic hairs on the seat is always good for a laugh.
Its because I’m a sharing sort of person I suppose.