Mark this as an extremely bizarre, but true, story but it happened recently in China. The monkey is a 3-month old Francois' Leaf Monkey to be born in the zoo in over 10 years. The species is highly endangered and is one of the most protected species in the nation.
Some people had given thrown peanuts to it, and the monkey swallowed one whole. Apparently, if he didn't pass the peanut quickly, it would endanger the monkey's life. The monkey is too small and young to take medicine, so they needed to... stimulate the passing through some other way.
So the caretaker washed the monkey's butt with warm water and licked its but for over an hour to stimulate the peanut's passing and save the monkey's life!