A friend of a friend told me that he was traveling through Asia. Then once he ordered a meal in a restaurant. He couldn't understand what it was. So he first got a good stock. Afterwards a waiter brought a turtle that was placed in the hot soup. Obviously, the turtle got very scared and defecated and urinated into the soup. Then the turtle was removed from the soup and the meal was finished. My personal opinion on this meal doesn't matter here. I'm just curious if this story could be true and if, how the meal is called and where you would have to go to get it.
After quite a bit of research, I wonder whether this isn't some sort of weird combination of stories.
Turtle soup exists. That's not under debate. For this you need to go to China or the US, especially in Louisiana.
Now most commonly, turtle soup in China is made with soft-shelled turtles. This is important, because they can urinate through their mouths when dipped in water!!
Now given that a lot of animals are prone to wetting themselves when frightened, then it would stand to reason that if instead of cooking the turtle, you dipped it in the water, it might well pee /poop in the water....
One other less sanitary means of doing it is demonstrated on this link, although it's not particularly kind to the turtle.
It's not quite a turtle, but the Chinese island of Hainan has a famous dessert with the euphonious English name of Chicken Poop Soup (鸡屎藤粿仔 jīshǐténg guǒzǐ).
Unfortunately (or not), the preparation of the soup involves no actual chickens, much less their excrement. The name comes from the plant Paederia foetida aka "skunkvine", thus named for the pungent smell of its crushed leaves, and known in Chinese as 鸡屎藤 jīshǐténg, lit. "chicken feces vine", since chicken feces also has a notable pong. The leaves are ground into flour, mixed with rice, and used to make dumplings/noodles for the soup.
If this tickles your interest, you can find some at Hainan Cuisine & Snacks in Toa Payoh, Singapore, check out their Facebook page for a yummy photo. And here's another restaurant in Hainan that sells it.
No, I believe this is merely an urban legend, perhaps motivated by a racist stereotype of Chinese people. It's not any more credible than "Chinese people eat tigers" sort of thing.
Turtles and tortoises are widely eaten across East Asia, and turtle soup is rather common especially in Guangdong Province. However, while Cantonese people have the notorious reputation to eat everything, we don't eat animal feces. AFAIK, some dishes in southwestern China may contain cow chyme, but I have never heard of any dish involving actual animal excrement.
Also, in Chinese cuisine, turtles are never cooked alive. Turtles are always butchered and blood-drained before cooking, otherwise they have a very unpleasant taste. This video explains how turtles are butchered in Chinese cookery. (WARNING: there is really a turtle being butchered in the video, so it might be considered too gory, bloody, and/or cruel by many. Click at your own judgment.)
So, while it is always difficult to prove a negative, I am confident to say that this story is little more than an urban legend. Meanwhile, there are many turtle dishes across East Asia; most involve cooking the turtle into a soup or stew, but none of them contain turtle excrement.
Source: I'm Cantonese, i.e. I hail from Guangdong Province in China, where such stories would likely have originated. I have consumed turtle soup on several occasions, although I haven't made my mind to eat the meat yet.