You will be asked to lie on the table on your left side. A needle is usually then inserted into your hand so that a light sedative can be given. The sedative will help you to relax, but it won’t put you to sleep. In some cases the test can be done without the sedative and you need to discuss this with the doctor before you sign the consent form.
After you have been sedated, the back of your throat will be sprayed with a bitter tasting anaesthetic to make it numb and to help you not to gag. A plastic guard will be put between your teeth to stop you from biting the endoscope. If you have false teeth (dentures) they will be removed. Your blood pressure and pulse will also be monitored.
The endoscope will be placed into your mouth and you will be instructed to swallow it down into your stomach. The tube is about the size of your ring finger, so there is plenty of room to breathe around it. Any extra saliva will be removed with a suction hose. The doctor will manoeuvre the scope into the right position and then air will be pumped in to make viewing easier.
Sometimes a special instrument can be inserted through the scope, and a small sample of tissue (a biopsy) removed. This is not painful. The doctor may also take some photos to refer to later. Some treatments can be performed while the endoscope is in eg, controlling blood loss from an ulcer or injecting big veins (like varicose veins) in the stomach. These treatments will make the procedure a little longer and will have been discussed with the doctor first.
Once the doctor is happy that everything has been seen, as much of the air as possible will be removed, and the scope will be gently pulled out.