What Causes Pain In The Coccyx While Standing?

Hi I have a question for my fiance, and his name is Emery. For the past month or more he has been having pain in his tailbone, and the pain would shoot down into the hips. He said it doesn't hurt sitting down, but more so when standing, and his pain level is about a 9. What do u suggest, or know of what it is that is going on?