Normally you will be told to take no food or fluids (nil by mouth) for at least 6 hours before your procedure but the times may vary between different hospitals. You should receive a letter from your hospital with a full explanation and a list of possible cautions or contraindications. These could include, enlarged veins in the oesophagus (the tube that connects the throat and stomach), difficulty swallowing food, or deformities of the neck. If sedation is going to be used you should bring a friend or relative as an escort to help you home and also to help remember any information given after the test. You should arrange to rest for the remainder of the day.