Why Liverpool's nickname is called the toilet?

Why?

I want to know the origin

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Liverpool rich toilet, the toilet is a sign of Liverpool, this point can be found Baidu to Wikipedia --- toilet. Why are stars called Rush, Liverpool has = "shit"? May also have some reasons for Liverpool's defense a perfect old man has been called "the same as airtight as the toilet," Again, the Liverpool team would be more like a toilet toilet, but the world-famous!

References: baike.baidu.com/view/7266.htm