Therapeutic Gastroscopy OesophagoGastroDuodenoscopy and dilatation

The aim of this leaflet is to help you make a choice about having a gastroscopy and dilatation of your food pipe (oesophagus). This is also known as therapeutic gastroscopy. The leaflet describes how the procedure is carried out and explains the benefits and risks.

Procedure Information

Please read this leaflet as soon as possible and well in advance of your appointment. If you do not follow the advice on how to prepare for your procedure it may not be possible to do it and you may have to return on another day.

Please bring this leaflet and consent form with you when you attend for your appointment

Helpline or enquiries   (8.30am to 5.00pm Monday to Friday)

For appointments and general enquiries

Boston           01205 445072

Grantham      01476 464366 / 01205 445072

Lincoln           01522 573849

Louth              01522 573849 / 01507 631415 / 631437

For procedure related enquiries (8.30am to 6.00pm Monday to Friday)

Boston           01205 446559

Grantham      01476 464085

Lincoln           01522 573016 / 01522 512512 ext 458669

Louth              01507 631236

For more information please see:

If you are worried about any symptoms you experience after this test you may ring the helpline numbers listed above. Out of hours please contact the NHS non-emergency service on 111.

Aim of the leaflet

The aim of this leaflet is to help you make a choice about having a gastroscopy and dilatation of your food pipe (oesophagus). This is also known as therapeutic gastroscopy. The leaflet describes how the procedure is carried out and explains the benefits and risks.

It is important that you follow the instructions given about stopping food and drink before the test. If you do not, you may find that your procedure has to be rearranged and you may have to return on another day.


You have been advised by your GP or hospital doctor to have a procedure known as a therapeutic gastroscopy.

If you are unable to keep your appointment, please notify the department as soon as possible as your appointment may be used for someone else. The booking team will arrange another date and time for you. Please bring this booklet with you when you attend.

Enclosed with this booklet is a consent form. Your signature is needed for the test to go ahead.

The consent form is an important document. Please read it carefully together with the information in this booklet. Please bring both the consent form and booklet with you to your appointment.

We may contact you a few days before your appointment to discuss the procedure and preparation in more detail. You will also be given the opportunity to ask questions in the department when you attend for your appointment. In case of any problems please contact the relevant endoscopy unit.

What is a gastroscopy?

The procedure is called OesophagoGastroDuodenoscopy (OGD) sometimes known more simply as a gastroscopy or endoscopy.

It involves looking at the upper part of the gut which includes the oesophagus (food pipe), stomach and the first part of your small bowel (duodenum) with a narrow flexible tube called a gastroscope. The scope is about the thickness of a little finger and is passed through the mouth and down into the stomach. The procedure is performed by, or under the supervision of, a specially trained doctor or nurse (endoscopist). A light and camera at the end of the gastroscope relay pictures onto a television screen.

Samples of tissue (biopsies) may be taken during the test. This is done through the scope. It does not cause any pain and the samples are kept to be looked at under a microscope in the lab. Photographs may be taken for your clinical records and may be used for teaching purposes.

We aim to make the procedure as comfortable as possible for you. Some people choose to have sedation (injected into a vein), while others prefer to only have local anaesthetic throat spray. More information about sedation and throat spray can be found on page 7.

Why do I need a therapeutic gastroscopy?

You have been advised to have this procedure to try and improve your swallowing and if needed, to help decide on further tests.

What is an oesophageal dilatation?

You have problems with swallowing due to a narrowing (sometimes called a stricture) in your oesophagus.

The oesophagus is stretched to widen the narrowed area and improve your symptoms. This is done through the gastroscope rather than a surgical operation.

The most common conditions that need this treatment are: Achalasia (a condition where the lower muscle in the oesophagus becomes very tight), scarring or strictures caused by acid reflux damage or surgery to the oesophagus, or a growth in the oesophagus.

Sometimes x-ray pictures are used with this procedure which involves some radiation exposure. If x-rays are needed the procedure will take place in the x-ray department.

What methods of dilatation are available?

There are two main methods used to stretch the oesophagus; firstly, the gastroscope is used to inspect and place a guide wire into your oesophagus, passing through the narrow part and onwards into your stomach.

An x-ray is sometimes used to help the endoscopist position the wire. Once the guide wire is in the correct place the gastroscope is withdrawn leaving the wire in place and the stretching equipment is passed into position along the wire.

In the second method, a guide wire is not needed as the dilating equipment can be positioned using the gastroscope alone. The dilating equipment is passed through a small channel within the gastroscope itself.

The dilating equipment used is a small inflatable balloon, which is positioned deflated and then inflated to certain pressures within the narrow area. As the balloon expands the oesophagus is stretched. Different sizes of balloon can be used in order to safely stretch the oesophagus to the size required to improve your symptoms.

The method that is used is chosen by the doctor and usually depends on the type of swallowing problem that you have. This will be discussed with you. Advice about eating and drinking after the procedure will be given to you before you go home.

What are the risks of the procedure?

Complications may be linked to the procedure or the sedation medicine.

Risks associated with gastroscopy

Sore throat, damage to teeth or bridgework (to reduce this risk your teeth will be protected with a mouth guard). Sometimes the procedure cannot be completed and a repeat test or alternative is needed.

Perforation or tear of the lining of the stomach or oesophagus (about 1 in 9000 cases). If this happens you may need an operation to repair it.

Bleeding may happen where a biopsy is taken. It usually stops on its own but may need cauterisation or injection treatment. In some cases a blood transfusion may be needed.

Risks associated with dilatation

Occasionally stretching causes some bleeding but this is usually not serious and settles quickly. You may be admitted to hospital if it does not settle.

The most serious risk is perforation (making a hole or tear) of the oesophagus or stomach. This can happen in about 1 in 100 cases and may need an operation to repair it. Sometimes the perforation is small, for example where the guide wire has caused a small puncture and this can be managed without an operation, but will always require admission to hospital. There is a higher risk of perforation (up to 10 in 100 cases) when there is a complex disease or a tumour of the oesophagus present.

These complications can normally be detected during or soon after the procedure and action taken.

Risks associated with sedation

Sedation can sometimes cause problems with breathing, heart rate and blood pressure. If any of these problems do occur, they are usually short lived. Careful monitoring by a specially trained endoscopy nurse means that potential problems are picked up early and dealt with quickly. The sedation can also cause small food particles to fall into the lungs which can trigger an infection (aspiration pneumonia). That is why it is important for your stomach to be empty (see advice below).

In extremely rare cases the procedure can lead to death. Current evidence suggest this may happen in around 1 in every 10,000 examinations.

Preparing for the investigation

Eating and drinking

For your safety, to reduce the risk of complications and give clear views, your stomach must be empty. Do not have anything to eat for at least 6 hours before the test and only have a light meal before this time. You may have small amounts of water up to 2 hours before your appointment time but other fluids such as milk (even in tea and coffee) are NOT allowed as they coat the stomach. You should have nothing to drink for at least 2 hours before the test.  If you do not follow this advice, your procedure will be rearranged.

What if I take regular medication?

Your routine medication should be taken as usual with a small amount of water.

Blood thinning medication (anticoagulants)

These include Warfarin, Dabigatran, Apixaban, Rivaroxaban, Edoxaban, Clopidogrel (Plavix), Ticagrelor, Prasugrel and Dipyridamole.

Your doctor should have discussed these medicines with you as they are important and can increase the risk of bleeding. If you are unsure please contact your Consultant’s secretary as soon as possible before your appointment for advice.


If you have diabetes controlled on insulin or tablets, please make sure the relevant endoscopy appointments team is aware so that the appointment can be made towards the beginning of the list. You will find more advice later in this leaflet.

Throat spray and conscious sedation?

Anaesthetic throat spray and conscious sedation are available to improve your comfort during the procedure. Some people choose to undergo the procedure with throat spray alone.

Anaesthetic throat spray

This is a local anaesthetic spray which numbs the back of the throat. It has an effect very much like a dental injection.

If you choose to have only throat spray you can go home on your own almost immediately after the procedure. You are allowed to drive and may carry on as normal, but you must not eat or drink until the sensation in your throat is back to normal.

Intravenous conscious sedation

The sedation is administered into a vein in your hand or arm just before the start of the procedure. This will not make you go to sleep but should help you feel more relaxed. It is important that you are awake for the procedure so that you are able to follow simple instructions during the investigation.

Please note if you have sedation into the vein, you will need someone to accompany you home and stay for at least 4 hours and if possible overnight. You are not allowed to take part in the following activities for 24 hours afterwards:

  • drive a vehicle
  • go to work
  • look after children on your own
  • operate heavy/dangerous machinery
  • drink alcohol
  • sign legally binding documents

What happens when I arrive?

When you arrive for your appointment please book in at reception.

It is our aim for you to be seen as soon as possible after your arrival. However, if the department is busy your appointment may be delayed. The department looks after emergency patients who will be seen first if needed.

A nurse will take you through to the admission room and ask you about your general health to check if you are fit to have the procedure. You will also be asked about your plans for getting home afterwards.

The nurse will make sure you understand the procedure and discuss any further concerns or questions you may have.  If you are happy to go ahead you will be asked to sign your consent form.

Your blood pressure and heart rate will be checked and a recording of your oxygen levels will be taken. If you are having sedation a cannula (small plastic tube) will be inserted into a vein (sometimes this is done in the procedure room).

What will happen during the procedure?

The nurse will take you through to the procedure room where you will be able to ask any final questions. If you have any dentures you will be asked to remove them. Any remaining teeth will be protected by a small plastic mouth guard which will be inserted just before the examination commences.

A local anaesthetic will be sprayed onto the back of your throat. It works quickly and will make your tongue and throat feel numb.

You will be asked to lie on your left side and a probe will be placed on your finger to monitor your oxygen levels. You will receive oxygen through the nose and if you are having sedation this will be given into the cannula in your vein.

Any saliva or other secretions produced during the investigation will be removed using a small suction tube, like the one used at the dentist.

The endoscopist will pass the gastroscope into your mouth, down your oesophagus into your stomach and then into your small bowel. Your wind pipe is deliberately avoided so you will be able to breathe normally throughout.

What will happen after the procedure?

You will be taken to the recovery area where your heart rate, oxygen levels and blood pressure will be monitored. Before you leave the department, the nurse or doctor will explain the findings and if any medication or further investigations are required.

For safety, following throat spray, you must not have anything to eat or drink for at about an hour after the procedure until the sensation in your mouth and throat has returned to normal.

It is strongly advised that your first drink after the procedure is cold and that you sip it to ensure you do not choke. You will be given more detailed advice about this after the procedure.

You may have a sore throat from the insertion of the tube which can last up to 48 hours. This will wear off but simple lozenges will help. You may also feel bloated if some of the air has remained in your stomach. To help this, sit upright and if possible walk around.

Pain relieving tablets, such as paracetamol, may be taken at home according to the manufacturer’s instructions.

If you have not had sedation you may feel able to return to work after the procedure but this varies from person to person. Some people feel they need to rest for a few hours afterwards. If you have been given sedation you are advised not to return to work for 24 hours afterwards.

Guidelines for people with diabetes

Treatment by diet alone

If you control your diabetes with diet alone, you simply need to follow the instructions given earlier in this booklet to prepare for your gastroscopy.

Treatment with tablets and/or insulin

You should inform the endoscopy appointments team about your diabetes and ask for a morning appointment.

Adjusting your diabetes medication to prevent hypoglycaemia

You may need to adjust your diabetes medication on the day of the procedure to reduce the risk of hypoglycaemia (‘hypo’ or low blood sugar level). As a result your blood sugar may be a little higher than usual but this is only temporary to maintain your blood sugars during the procedure and you should be back to your usual level within 24 to 48 hours. If needed please contact the Specialist Diabetes Nursing Team on 01522 573074 well in advance of the appointment for advice.

On the day of the procedure carry glucose tablets in case of hypoglycaemia. As these are absorbed quickly through the tissues of the mouth, if sucked they will not interfere with the procedure (do not chew). If you have symptoms of low blood sugar take 4 to 6 tablets initially, followed by a further 4 to 6 if symptoms continue after 10 minutes.

Blood glucose monitoring

If you usually test your blood sugar level, check it as usual on the morning of the procedure and bring your equipment with you to the appointment. If you do not usually test your blood, do not worry your blood sugar will be checked when you arrive for the procedure.

Report to the nursing staff if you have needed glucose before arriving for your appointment and tell them immediately if you feel ‘hypo’ at any time during your visit.

What must I remember?

  • If you are unable to keep your appointment please notify the endoscopy department as soon as possible. Telephone numbers are given at the beginning of this leaflet
  • Follow the instructions about food and drink or your procedure may be postponed
  • It is our aim for you to be seen as soon as possible after your arrival. However, the department is very busy and your appointment may be delayed. If emergencies occur, these patients will be seen before less urgent cases.
  • If you have opted for sedation into the vein please arrange for someone to collect you and for someone to stay overnight if possible. Your activities afterwards are limited as advised in the sedation section of this leaflet.
  • The hospital cannot accept any responsibility for the loss or damage to personal property during your time on the premises.