Having had the procedure done ins everal different facilities I can tell you the staff will not let you go unless someone comes in and signs for you. In other words if there is no one to get you and check you out you stay put.
On that note, I drove myself to a test once. A friend came over after it was done and checked me out. I then walked down with him to my car and I drove myself home. I felt fine but no doubt if something happened I would have gotten into trouble. Just not worth taking the risk.
Dante - Boost? Was that on your list of things you could have? I definitely could have used a Boost or two but my instructions were clean liquids only. I was limited to water, juices (with no pulp), popsicles, broth and jello. It amazes me how different everyone's instructions are. No two alike.