That is one of the strangest things I've heard in a long time. I would question whether or not this doctor has had any malpractice issues and isn't comfortable taking patients who might be a bit more of a potential risk. I don't know of many bipolars who haven't been hospitalized, or at least shouldn't have been at some point.

Just as a curiosity, it might be interesting to check the doctor's record on the state medical licensure website to see if he's had any adverse actions taken against him. Whatever the case, I would run as fast as you can to the next phone number on your list and avoid this guy like the plague.