What is a pre op transsexual?

Pre-op means pre-operative. They are a transsexual person who has not had the surgery yet. A person is born with transsexualism, and they get the surgery to cure them of it and make them as close to what they should have been all along as they can.

A transsexual person is not the same as some man who chooses to become transgender. A TS person is born with the TSism and transitions to become whole. A non-op transgender is typically a man who attempts to live as a woman (only partially transition) and keep their original genitalia. They often have the goal of being seen as a third gender, or for fetish or entertainment reasons. If you are not born with TSism, you can never get it, and TS persons actually hate having transsexualism. A person is born with TSism, but chooses TGism. A person who chooses TGism cannot suddenly turn into a person born with the condition of transsexualism and the burning need to cure it with hormones and surgery.