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．