Gastroscopy West Mid Site

*Patients are no longer required to take a covid swab test before an endoscopy procedure. However, we will continue to assess patients on arrival. If you are symptomatic, we will ask you to take a covid swab test before your procedure takes place.

What is a gastroscopy?

A gastroscopy, also known as an endoscopy or OGD is a test in which a long flexible telescope called an endoscope is passed through the mouth allowing the Endoscopist to look directly at the lining of the oesophagus (gullet), stomach and duodenum (small bowel).

Sometimes a biopsy - sample of tissue – is taken for analysis (testing) in the laboratory. The tissue is removed through the endoscope using tiny forceps. This is not painful.

Some people will require treatment through the endoscope to treat/prevent bleeding, or to dilate up the oesophagus. If this is needed the procedure will be explained and may take longer.

There is a considerable variation in the way people react to this procedure and the sedation. General anaesthesia is not required. The procedure is safe but may be unpleasant and at times uncomfortable.

Do I need to fast before the test?

Yes, it is essential your stomach is empty for us to perform the gastroscopy. Therefore you must not eat for at least 6 hours before the examination. You may drink small sips of clear fluids (water, black tea or black coffee) until two hours before the procedure.

What are the risks and benefits?

The benefit is that this procedure will help us to investigate your symptoms and it may help us to treat you.

There is an extremely small risk of bleeding or a tear in the lining of the gut (perforation 1 in 9000), which may require urgent treatment, blood transfusion or an operation. Gastroscopies also involve a slight risk of damage to crowned teeth or dental bridgework.

What should I do before I come in?

If you are having sedation, you must organise an adult to take you home after the test and be with you for 24 hours. Please ensure the nurses have the contact details for your escort prior to the procedure. A nurse from the unit will call your escort once you are ready for collection. You do not need to bring anyone with you to your appointment, unless they are acting on your behalf e.g. interpreting for you.


If you are taking any of the following medicines please stop taking them accordingly:

1 week before the test:

  • Omeprazole (Losec), Lansoprazole (Zoton), Esomeprazole (Nexium)

48 hours before the test:             

  • Ranitidine (Zantac), Cimetidine (Tagamet)

These tablets are protecting the lining of your stomach and if you stop taking the medication it will help us to get a clearer diagnosis.

It is not necessary to stop these medicines if your procedure is for Barrett’s surveillance, or to assess response to treatment for oesophagitis or an ulcer.

Unless you have been advised otherwise, you should take any other usual medicines normally (with a few sips of water). If you are diabetic please let us know in advance.

If you are taking any of the following medicines, please inform the pre-assessment nurse or a member of the Endoscopy team for further instructions:

  • Warfarin, rivaroxaban, apixaban, dabigatran, edoxaban
  • Clopidogrel, prasugrel, ticagrelor
  • Aspirin
  • And any other medication used to thin the blood (anti-coagulant)

What will happen when I come in?

On arrival to the endoscopy unit please report to reception where the receptionist will check your personal details. You will be asked to take a seat in the waiting area until you are collected by a nurse, and taken through to one of our admission rooms.  Please leave any valuables at home, as we cannot be responsible for any valuables lost whilst you are in the unit.

On admission a nurse will review your pre-assessment form (Medical history and current medications) that you should have completed online. We will also take your blood pressure and pulse.   

Prior to the test you will be seen by the Endoscopist. This is an opportunity to discuss the test before you sign a consent form. Please ask any questions you may have. It is important that you understand what is going to happen.

Sedation or Throat Spray?

You will be offered the choice of sedation or local anaesthetic throat spray.

Throat spray - With this method, sedation is not used. Your throat is numbed with a local anaesthetic spray which will help the endo scope to go down. The benefit of choosing throat spray is that you are fully conscious and aware and can go home unaccompanied. You are permitted to drive, but you must not have anything to eat or drink for about an hour after the procedure until the sensation in your mouth and throat has returned to normal.

Sedation via a needle - If you choose to have sedation, we aim to use enough sedative to relax you. We do not send you to sleep but we will do our best to make you as comfortable as possible. The sedation will be administered into a vein in your hand or arm.  You will need to rest in the department for at least an hour afterwards.

Please arrange for an adult escort collect you from the unit and be with you for 24 hours. We cannot escort you home. 

Please note, the sedative will make you drowsy and even if you feel wide awake your reactions may still be affected. You may find it difficult to concentrate and you may forget things that you have been told after the procedure. The nurses will give you written discharge information. This includes the advice that for 24 hours after sedation you should not drive, ride a bicycle, operate machinery, take sedatives or drink alcohol, or sign legal documents. 

What will happen during the test?

In the procedure room you will lie on a trolley (narrow bed), on your left side. Two nurses and the endoscopist will stay with you throughout the test.

You will be asked to bite on a small plastic mouthpiece to help keep your mouth open. This will also help to protect your teeth during the test. Dentures have to be removed if they are loose.

During the test you may be given oxygen through little prongs that fit just inside your nostrils. Your blood pressure, pulse and oxygen levels will also be monitored.

When the endoscope is passed through your mouth it is likely to be uncomfortable. It may make you feel sick or you may retch. The endoscope will not interfere with your breathing. During the test air is passed down the endoscope into your stomach to get a clear view. This may make you burp. The air is sucked out at the end of the test.

If you get a lot of saliva in your mouth, the nurse will clear it using a sucker (the sort of tube that is used when you go to the dentist).

What happens to my medication?

We will talk to you before you go home about any changes/additions to your medications.

How long will I be in the endoscopy unit?

The whole procedure usually takes 5–10 minutes; however please expect to be in the department for 1-2 hours – having pre-procedure checks, the procedure and for recovery after the procedure.

Your appointment time in Endoscopy is approximate because some procedures may take longer than expected and emergency procedures need to take priority.

After you go home

After your procedure, you may feel bloated if some air remains in your stomach. It is advisable to sit upright and if possible walk around to help relieve this. Warm drinks and peppermints will also help you to pass the wind. You may have a sore throat, which can last up to 48 hours. Taking throat lozenges will help. Pain relieving tablets such as paracetamol may be taken according to manufacturer’s instructions.  If the pain continues, or you have concerns or questions, please contact the Endoscopy Unit from 8am–6pm on 020 8321 2585/5191 - after 6pm call 020 8560 2121 and ask for the on call gastroenterologist. 

This leaflet has been written by the staff working in the Endoscopy Unit at West Middlesex University Hospital. We hope you find it useful. If, after you have read it, you have any questions or concerns; please contact us on 020 8321 2585/5191.

If you would like to change your appointment time or date please contact the endoscopy booking team on 020 8321 5752 or email us

How to find us

The Endoscopy Unit is located on the ground floor of the Main Hospital Building in the East Wing.

Getting here:


Ciara Callan