Why do many places in China call going to the toilet "relieving oneself"?

Toilet is a well-known saying, which means to urinate or go to the toilet. It is called "convenience" or "internal emergency". The origin of the word jieshou is legendary among the people. In the early Ming Dynasty, during the migration of Sophora japonica in Hongdong, Shanxi, officials tied their hands behind their backs and untied them when they had to go to the toilet in an emergency. Nowadays, it is generally believed that relieving oneself means going to the toilet or going to the toilet.