You have been advised to have a gastroscopy, which you may also have heard being called an endoscopy or OGD (meaning an oesophageal-gastro-duodenoscopy). A gastroscopy will help us to investigate the cause of your symptoms.

It is important that you read this page before your appointment so that you understand this procedure and the preparation involved.

If you have diabetes and you are receiving treatment please leave a message on the Medication Advice Line. The number is at the bottom of this page. If you are using an insulin pump we would like your BM to be 7mmol/L. Please call your local pump team if you need further advice.

If you are taking any medication that thins your blood other than aspirin (which you can continue to take) please contact the Medication Advice Line. This is very important as your procedure may be delayed if you do not get advice.

If required, you may be asked to attend the radiology department for imaging tests on the same day as your gastroscopy.

What is a gastroscopy?

Gastroscopy is an investigation to look directly at the lining of the oesophagus (gullet/food tube), the stomach and around the first bend of the small intestine (the duodenum). A gastroscope is passed through the mouth, down the gullet and into the oesophagus.

A gastroscope is a long flexible tube, thinner than your little finger. It has a bright light at the end (this is not hot), which is necessary to be able to see the lining of the stomach.

Pictures are transmitted on to a screen where any abnormalities can be seen. Unfortunately you will not be able to see the screen as it will be behind you.


A biopsy is a small sample of tissue that may be taken from the lining of your gut or bowel for further examination in the laboratory. It is taken using sterile biopsy forceps through the scope. This will not be painful.

What is dilatation?

A dilatation can be performed if a narrowing of the gullet (oesophagus) is found. This means stretching the narrowing to improve your swallowing. Usually the need for this procedure has been identified before your appointment.

Dilatation is not available in Stroud or Cirencester hospitals.

What is banding?

Banding is a way to treat oesophageal varices. These are like varicose veins in your oesophagus. The endoscopist will place special elastic bands around each of the varices. This stops the blood supply to these veins and they eventually disappear. This will not affect the normal blood supply to the oesophagus.

This procedure is not available in Stroud or Cirencester Hospitals.

What is stenting?

An oesophageal stent is an expandable tube made of a flexible metal which allows it to expand over a period of hours. This will make it easier for you to swallow food and fluids. Your consultant will choose the right stent and size for your needs.

This procedure is not available in Stroud or Cirencester Hospitals.

Alternative procedures

The main alternative to a gastroscopy is a barium meal X-ray. This can look at the stomach, but does not allow biopsies to be taken. Please note that an alternative procedure will not be available on the day.

Preparing for your procedure

To allow a clear view during the procedure the stomach must be completely empty. You are therefore asked not to have anything to eat for at least 6 hours before your appointment time.

You may drink water up to 2 hours before your appointment time.

You will be offered a choice of sedation and/or throat spray.

On admission

On arrival at the department you will be seen by a nurse who will check your personal details.

You will be asked a series of questions about any operations or illness that you may have had or are presently suffering with.

Please bring a list of all medications you are currently taking.

The nurse will also ask if you have any allergies or reactions to medicines or foods.

You will be asked if you want sedation. If you are considering sedation you will be asked to confirm that you have a responsible adult to escort you home when you are ready for discharge. You must also have a responsible adult with you at home for 24 hours following the procedure.

The test and possible complications will be explained so that you understand the procedure and any risks involved.

You will be asked to sign a consent form. By signing this form you will have agreed to have the test performed and that you understand why it is needed. This does not take away your right to have the test stopped at any time.

For the time that you are in the department we want to provide a safe, supportive and pleasant environment. Please do not be afraid to ask if you have any worries or questions at this stage.

For this procedure you will not need to remove your clothes but ties may need to be loosened and shirts opened if tight at the neck.

Please remember that your appointment time is not the time you will have your procedure. There will be a wait between your admission and having your test done.

A nurse or doctor will escort you into the room where your procedure will take place. A nurse will stay with you throughout the test. You will be made comfortable on a patient trolley lying on your left side, with your knees slightly bent.

Sedation or throat spray

Intravenous sedation and/or local anaesthetic throat spray can improve your comfort during the procedure. Intravenous sedation will make you lightly drowsy and relaxed, but not unconscious (asleep).

Anaesthetic throat spray

Throat spray is a local anaesthetic spray used to numb the throat. This can be given on its own or alongside sedation.

As the gastroscopes have become thinner, many patients are happy for the procedure to be carried out without sedation and to have throat spray instead. The throat spray has an effect very much like a dental injection.

The benefit of choosing throat spray is that you are fully conscious (awake) and aware during the procedure. You will be able to go home unaccompanied almost straight away after the procedure.

You will also be allowed to drive after discharge and carry on with your normal routine.

The only restriction is that you must not have anything to eat or drink for about an hour after the procedure.

This will allow for the sensation in your mouth and throat to return to normal.

It is strongly advised that your first drink after the procedure should be cold. This should be sipped slowly to make sure that you do not choke.

Intravenous sedation

Sedation will be given into a vein in your hand or arm. This will make you feel lightly drowsy and relaxed but not unconscious (asleep). You will be in a state called conscious sedation. This means that, although drowsy, you will still hear what is said to you and therefore will be able to follow simple instructions during the procedure. You will be able to breathe normally throughout the procedure.

While you are sedated we will check your breathing and heart rate so changes will be noted and dealt with accordingly. For this reason you will be connected by a finger probe to a pulse oximeter which measures your oxygen levels and heart rate during the procedure. Your blood pressure will also be recorded. Oxygen will be given to you via a mask or a small sponge inserted into your nostril.

Please note that if you decide to have sedation you are not allowed to drive, drink alcohol, operate heavy machinery or sign any legally binding documents for 24 hours following the procedure. You will also need someone to accompany you home and stay with you for 24 hours.

If suitable, Entonox® (gas and air) is also available during the procedure either as an alternative to sedation or as well as.

This will help to control any discomfort. You will not need a responsible adult to stay with you if you choose Entonox® only. (A separate leaflet has been provided).

If you have experienced or suffered with any of the following within the last 12 weeks, Enotonx® will not be suitable for you.

  • Pneumothorax
  • Air embolism
  • Emphysema/COPD
  • Recent ear/eye surgery
  • Head injury with impaired consciousness
  • Bowel obstruction
  • Scuba diving
  • Decompression sickness

The procedure

In the examination room any dentures will be removed and a local anaesthetic spray will be applied to the back of your throat to numb it for the procedure.

To protect your teeth and the gastroscope, a plastic mouth piece will be put between your teeth or gums if dentures have been removed. The tube will then be inserted through the mouth piece. When it reaches the back of the throat you may be asked to swallow to help the tube go down into the stomach. This will not interfere with your breathing.

Some air will be passed through the instrument to blow up the stomach and allow a clearer view. You may feel wind like discomfort and belch some air up during the test. Please do not be embarrassed.

Any saliva in your mouth will be removed using a small suction tube. When the gastroscope is taken out most of the remaining air in the stomach will also be removed. The gastroscopy will normally take about 5 to 15 minutes.


Sedation can occasionally cause problems with breathing, heart rate and blood pressure. If any of these problems do occur, they are normally short lived. Careful monitoring by a fully trained endoscopy nurse makes sure that any potential problems can be identified and treated rapidly. Older patients and those who have health problems, for example, people with breathing difficulties due to a bad chest may be assessed by a doctor before being treated.

Minor complications with sedation happens less than 1 in every 200 examinations. A few people are excessively sensitive to the sedation we use and become too sleepy.

This effect can be rapidly reversed with another injection.

Major complications with endoscopies are very rare (less than 3 in 10,000) and death arising from these is extremely rare (less than 1 in 30,000). The main serious complication is perforation (a tear) of the oesophagus (gullet) or bowel, which may need an operation and stay in hospital. This complication is more common if a stretch is performed for narrowing of the gullet (less than 1 in 200). It would not be normal practice to stretch the gullet without discussing the risks and benefits with you first. If banding is performed, in less than 1 in 100 cases bleeding can be started.

After the procedure

After the gastroscopy is completed the nurse caring for you during your test will take you from the endoscopy room and to the recovery area.

Your pulse and blood pressure will be monitored as needed. This is called the recovery period. You may feel a little bloated or have some discomfort in your lower abdomen after the test. You will need to stay in hospital for about an hour after this procedure depending on how you recover from the sedation.

If sedation has not been given you will be allowed home straight away.

Normally you do not see the person who performed your procedure before going home.

Your nurse will tell you the results of the test before you are discharged.

If you have had sedation it is a good idea to have someone with you at this discussion as many people find they forget what has been said to them.

If a sample (biopsy) has been taken, the result can take up to 5 weeks to process. You may be given an outpatient’s appointment to return for review. Alternatively the results will be forwarded to your GP and you will need to make an appointment to see him/her. A report of the procedure will automatically be sent to your GP.

Going home

If you have had sedation it is essential that someone takes you home and that there is a responsible adult to stay with you for 24 hours.

Important note: You may go home by taxi but you must have someone to accompany you on the journey.

For this period of time you should not:

  • Drive a car, motorbike or ride a bicycle.
  • Drink alcohol.
  • Operate machinery or do anything requiring skill or judgement.
  • Make important decisions or sign any documents.

If no sedation has been given the above paragraph does not apply.

If you have received Entonox® for pain relief you will need to stay in the department for 30 minutes before going home

An advice sheet incorporating this information will be given to you before you leave; this is your discharge letter.

Gloucestershire Hospitals NHS Foundation Trust Endoscopy units are training centres. Registrars and nurse endoscopists regularly attend endoscopy procedure lists. Please let the admitting nurse know if you have any concerns about this.

Contact information

Appointment Enquiries

Cheltenham General Hospital
Tel: 0300 422 6899
Monday to Friday, 8:30am to 4:00pm
Gloucestershire Royal Hospital
Tel: 0300 422 6351
Monday to Friday, 8:30am to 4:00pm

Medication Advice Line (Answer Machine)
If you have any questions relating to your medication, please leave a message. A member of staff will return your call normally within 24 hours, week days only.
Cheltenham General Hospital
Tel: 0300 422 3370
Gloucestershire Royal Hospital
Tel: 0300 422 8232

Other Endoscopy Units
Cirencester Hospital

Tel: 0300 421 6294
Monday to Friday, 8:00am to 6:00pm
Stroud General Hospital
Tel: 0300 421 8073
Monday to Friday, 8:00am to 6:00pm

Reference number GHPI1081_08_20
Department Endoscopy
Review due August 2023
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