The examiner will want your stomach empty during the procedure. You will be instructed to fast before the test. Usually, you are requested to take nothing by mouth after midnight. However, if the test is scheduled for later in the day, most units permit a light breakfast.
You should inform your doctor if you are diabetic to appropriately plan your diet and insulin requirement. You should also inform your doctor of all medications you are taking, both prescription and over-the-counter, to determine your dosing schedule for the day of the procedure.
If you are taking anticoagulants or aspirin, you should make your doctor/endoscopist aware of this when scheduling the test. If he or she agrees, aspirin should be stopped a week before. Be aware that several over-the-counter medications contain aspirin.
If you are to have sedation for the test, you should arrange to have someone pick you up when you have recovered from the drugs.
As with all medical procedures, you will be asked to sign a consent form that certifies that you understand the risks and benefits of the procedure and that your doctor has explained these to you.
This is an opportunity for you to ask any questions that you may have. Normally, endoscopy is very safe. However, perforations of the upper gut have occurred, usually when the area being examined is diseased. There is a risk of bleeding with certain procedures done through the endoscope, which is why drugs that interfere with clotting such as aspirin or anticoagulants should be stopped and normal clotting achieved before the test.
For a routine endoscopy, sedation is often given. There are many local variations about if, how, and when sedation is given. Some centers may normally provide only local anesthesia to the throat. Usually, sedation is given by intravenous injection in the examination room immediately before the test begins. There are many sedatives and relaxants in use for this purpose. Occasionally, a fast acting oral or sub-lingual (under tongue) pill is given sometime before the procedure. For the most part, the medications are safe and effective, but all require a period of recovery after their administration.
It is important to realize that you are not put to sleep, and that you need to be conscious and cooperative throughout. This method is called "conscious sedation."
The advantages of sedation are that it reduces the tendency to gag during introduction of the endoscope and lessens the inevitable anxiety associated with the test.
The disadvantages are that you must recover for a period (usually an hour) before going home, you must have someone take you, you may not remember or fully understand the explanation of the procedure given after the test, and there are rare adverse reactions to the sedating drugs. The endoscopy nurse or doctor will explain information specific to the particular method of sedation used. Too much sedation (and tolerances differ) risks arrested breathing or aspiration of gastric contents into the lungs (another reason for fasting prior to the procedure). If sedation is given, a device clipped to your finger permits the nurse to monitor your heart rate and blood oxygen saturation.
Before starting, the endoscopist or the endoscopy nurse will apply a topical anesthetic to your throat. This is to help you swallow the tube without gagging. The local anesthetic used is usually lidocaine and it may be applied as a spray, or as a gel that you swallow. It has a bad taste, and there have been many attempts to flavor it – with little success.