Sorry for bagging you again. i visited a doctor for second opinion. at the end of our appointment he said '' get outta here'' in a neutral tone. what did he mean by this? should i go back?

Probably this was intended to be tongue-in-cheek, even humorous. If so, it seems likely that whatever problem you had is gone or otherwise unimportant. Still, doctors are responsible to communicate clearly, so you should ask him. I suggest starting with the assumption that he didn't mean anything negative.

Context is needed in such circumstances that are hard to judge regardless. I will say that is an unusual exit greeting in the medical office setting. The easiest to figure out if you need to go back or not would be to review your after the visit papers in which next steps are usually formulated.