B’H you told him, but it wouldn’t have made a difference, as far as if you would have stopped breathing totally, because that’s what anethesiologists do. Most operations they give you drugs that produce General Anethesia, which means they put you to sleep and stop your breathing. Then they breathe for you, with either a BVM or a respirator, with sometimes putting a tube into your trachea (windpipe). With the endoscopy, they usually don’t need or do GA; they just make you a little groggy.
Enough with teaching medicine -Go see a doctor!