It would be nice if every office provided roomy cloth gowns. But there's no rule that says you can't provide your own exam gown. Call prior to your appointment and inquire if your doctor prefers gowns that open in the front or the back. Keep in mind that your gown may get stained, especially if you are having a procedure. Bring something that you won't care if it gets ruined. A wrap around robe or loose dress with a front zipper is fine.