I never did mention anything on this forum before. He brought it to my attention one day while i was in his office. I guess because of the anorexia, cutting, "not taking care of myself," identity disorder?, ect.. Heck if I know, im just the patient.
I can see the therapist wondering about borderline personality disorder, perhaps, and that can be misdiagnosed as bipolar disorder. I just don't see DID as likely from what you've told us about yourself.
Then again, the therapist may have access to more information that we do. I just find it puzzling.