喝河水很容易闹肚子。

It can get a tummy upset by drinking river water.

你们这是否卖治闹肚子的药呢？

Do you guys carry medication for upset stomach?

她是不傻，可是她闹肚子了，所以，她还是怀孕了。

She isn't silly, but she suffered from diarrhea, so, she was pregnant.