Well with water that's not safe to drink, but used to cook all the time... so it is a common thing for them. They think nothing about it, just like if you make the mistake of using a squat toilet without a stall door, they will stare and want to have a conversation the entire time.

With the quality of food you have in China, the way they process food, keep food refrigerated (if they do) and the things they put inside the food when they cook.....it's pretty easy to have "laduzi" for anybody, even a Chinese.....

I have never had a normal crap in all my time in China. When I talk about this with friends at home they don't get it and are grossed out. In China it's a great discussion...even at dinner!

Laduzi, the Montezuma's curse, the runs, whichever way you call it, it is the same stinking mess.  While for us it is sort of a very private condition, not to be discussed in public, for others simply it is a natural body function, no problem talking about it.  Maybe in a way is like farting in public, while we blame the dog, they look at eachother and smile.