"我要去洗手间"用英语怎么说？谢谢

有很多种表达方式：
1)I want to go to WC.
2)I want to go to toilet.
3)I want to go to wash-room.
比较隐晦的说法： I have to answer nature's call.或 I have to answer the call of nature.我要响应大自然的召唤．
比较有失大雅的说法:
1) I want to piss.我要小便．
2) I want to shit.我要大便．
还有很多俚语，在这里就不一一指出．

I have to go to the john.
I have to wash my hands.
I'd have a wash.
I have to answer the nature's call.

都是非常婉转地道的说法。

男士可以说i‘m bursting
女士可以说 i'd like to power my nose

where is the washing room

I need to leave for a moment

I will go to wash my hands.