Colonoscopy without an Escort?

For a routine colonoscopy the hospital/clinic requires you to have an escort pick you up and take you home. It has to be someone you identify beforehand, so you can't just call a cab or Uber, or walk, or wait in the lobby until they determine you are "recovered" sufficiently. I don't think a "leaving against advice" waiver is even an option. Has anyone figured out a way to circumvent this?