I am from an area where people just say they need the loo to pee or poo. In formal situations, when meeting just strangers, we are a bit less open and call it 'need the toilet' but I know that in other countries they are a lot less open about it.
Small children, at the potty training age, are quite open about what they do and such, but soon they learn the local 'polite' way to say things and it is frowned upon if they even mention the words again.
The words acceptable are likely very clear in the area but likely hard to use for those not brought up in the same culture.
I have heard words as 'nr 1' and 'nr 2' but also some that I could not even understand well enough to remember.
So as a foreign tourist, I know I should not use the words I would use at home, not even in the more polite translations into English.
But what is acceptable?
I get by with asking for the 'ladies' and looking a bit uneasy, but I know it will still be seen as impolite in some societies. In the past I have asked for the bathroom to be shown a bedroom, by the person I was asking not understanding the evation.
Can you tell me what to use and in what situation this is acceptable?
Location and social class might be needed to get a good picture.
To keep this from going too wide, I feel I restrict it to just English speaking countries but I would not mind learning English equivalents for what people use in other language areas.