I had a horrible experience with mine. Felt i was suffocating. Retching and gagging all the time. And i could feel the tube down inside. It was terribly uncomfortable and i could hardly stand it. I had the urge to pull the tube out and the nurse held my hands down. It was such a relief when they took it out. I have had full colonoscopies with no sedation and did not find it anywhere near as bad as the gastroscopy. I am due for another and i have to say i am dreading it. My husband has had 2, being diagnosed with coeliac disease. He said the first one was not too bad but the second time he had a bad experience similar to mine. Perhaps it depends on the experience and expertise of the particular doctor.