Sandra, After my bio of my tongue and tumor on the floor of mouth were determined to be cancer, my doctor did and endoscopy. There is not a lot of prep work and they do it as an outpatient. This procedure checks not only your throat, but all the way down to your stomach. I had another one done last November because I was experiencing pain in swallowing. It turns out that all was well and it was just scar tissue forming where they did my trachea. If you have any more questions, let me know. Take care. Anne.