He went to the toilet in middle of the night.

他半夜里去了趟厕所。

How did he feel after he went to the toilet?

他上厕所后感觉如何？

Inside the terminal he went to the man's bath room. He went to the toilet but that didn't help.

在候机楼里，他去了那个男卫生间。他上了厕所，但没用。

So you can say, " I went to the toilet."

所以你可以说，“我去厕所了。”

Noticed them when I went to the toilet. But they won't shoot.

我去厕所的时候注意到了他们。 但他们不会开枪。