Your personal statement is where you explain "why medicine". Briefly describe 2-3 experiences that you have had, and why those helped you decide on this profession. If something you did while shadowing falls into that criteria, then, by all means, include it. When writing about the experience, only provide enough detail about the shadowing as is necessary to tell the story.
Also, the PS is not a place to rehash your application. If you are just re listing the things you did, you will be wasting your time and money.