Your health expert: Dr Alistair McNair, Consultant Gastroenterologist
Content editor review by Dr Kristina Routh, March 2021
Next review due March 2024

A gastroscopy is a test to look inside your oesophagus (the tube that carries food from your mouth to your stomach), your stomach and the first part of your small bowel (duodenum). You may have a gastroscopy to help find what’s causing your symptoms. You can also have certain treatments during a gastroscopy.

What is a gastroscopy?

A gastroscopy is a type of endoscopy. This means the procedure is carried out using a narrow, flexible tube called an endoscope. This has a light at the end and a camera to allow your doctor to see images of your insides on a screen. You can find out more about what’s involved in our section below: What happens during a gastroscopy?

Other names for a gastroscopy are ‘upper gastrointestinal endoscopy’ and ‘oesophago-gastro-duodenoscopy (OGD)’.

Your doctor may recommend you have a gastroscopy to find out why you’re having certain symptoms. These include:

  • indigestion that doesn’t go away with treatment or that returns when you stop treatment; you may have acid reflux or discomfort in your upper tummy
  • difficulty when you swallow (food sticking in your oesophagus) or pain when you swallow
  • pain in your chest or upper tummy
  • being sick (vomiting) repeatedly
  • vomiting blood or having very dark tar-like blood in your poo

A gastroscopy helps your doctor to confirm or rule out suspected medical conditions. These include:

Your doctor may take small samples of tissue (a biopsy) during the gastroscopy.

Your doctor can also use a gastroscopy to carry out certain treatments, such as:

  • stopping bleeding
  • removing small growths
  • removing objects which have got stuck in your throat
  • widening your oesophagus if it has become narrowed

For more information on this, see our FAQ below: Can my doctor treat my condition during a gastroscopy?

Preparing for a gastroscopy

A gastroscopy is usually done as a day-case procedure in hospital. This means that you’ll be an outpatient and you won't need to stay overnight. Before your gastroscopy, you’ll be given information about what’s involved. This will tell you anything you need to do to prepare for your gastroscopy. It’s important that you follow any advice you’re given. If you don’t, it may not be possible to have the procedure.

Before coming to hospital

The information you get will tell you if you need to stop any regular medicines you’re taking. Some indigestion medicines (called proton pump inhibitors) can mask problems in your oesophagus or stomach. If you take these, you may need to stop them for one or two weeks before your gastroscopy. Your doctor will let you know if they want you to stop taking any indigestion medicines before your procedure.

You must let the hospital team know if you’re taking medicines to thin your blood. These include aspirin, clopidogrel and warfarin. Your doctor will tell you if you should stop taking them for a while. This will depend on which medicine you take and what the gastroscopy will involve. If you continue to take medicines that should be stopped, you may still be able to have a gastroscopy. But you probably won’t be able to have a biopsy or a treatment procedure.

You should arrange for someone to take you home and, if possible, stay with you for 24 hours afterwards.

On the day

Your stomach must be empty during your gastroscopy. This means you shouldn’t eat or drink for four to six hours beforehand. It’s important to follow the advice your hospital gives you.

Tell your doctor about any medicines you’re taking. This includes prescribed medicines and those you buy over the counter.

Your doctor will talk to you about what will happen before, during and after your procedure. They’ll ask if you want to have a local anaesthetic or sedation or both. The local anaesthetic is a spray that numbs your throat area. The sedative will make you drowsy and more relaxed. It’s given as an injection at the start of the procedure.

Ask your doctor to explain the pros and cons of having sedation or local anaesthesia. For instance, you may be more comfortable with a sedative. But if you choose this, you’ll need to have someone to take you home and keep an eye on you afterwards. If you choose to have the local anaesthetic spray, it may feel a little more uncomfortable at the time. But you won’t be drowsy afterwards.

You’ll have the chance to ask questions so that you understand what will happen. Once you understand the procedure and if you agree to have it, your doctor will ask you to sign a consent form.

What happens during a gastroscopy?

A gastroscopy usually takes only five to 10 minutes, though it might take longer. But you should expect to be in the hospital for a few hours. Your gastroscopy will be done by a doctor or a specialist nurse.

You may be asked to take off your shirt or top and put on a hospital gown. If you have any false teeth or you wear glasses, you’ll need to remove them. You can leave contact lenses in.

If you’re having a local anaesthetic, your doctor or specialist nurse will spray the back of your throat. If you're having a sedative, this will be given through a fine tube into a vein in your arm. Your heart rate and oxygen levels will be checked using a sensor attached to your finger.

You’ll be asked to lie on your left side. Your doctor or specialist nurse will place a guard into your mouth to protect your teeth. They’ll then pass the gastroscope through the opening of the guard into your mouth. You’ll be asked to swallow to let the gastroscope pass into your oesophagus and down towards your stomach. This may be uncomfortable for a few seconds, and it’s usual to gag once or twice. The discomfort usually passes quickly.

As the gastroscope passes down, your doctor or specialist nurse watches images on a nearby screen. They will be able to see the lining of your oesophagus, stomach and duodenum. They may put some air down the gastroscope to inflate your stomach, so they can see better.

If needed, your doctor or specialist nurse can pass special forceps down the gastroscope to take a biopsy (a small sample of tissue). They will then send the samples to a laboratory for testing.

You can have some treatments through the gastroscope. For more information, see our FAQ below: Can my doctor treat my condition during a gastroscopy?

An image showing where a gastroscope is passed

What to expect after a gastroscopy

If you had a sedative, you’ll need to rest in a recovery area until the effects of the sedative have passed. You’ll be able to go home when you feel ready, usually after about an hour. You will need someone to drive you home.

If you had a local anaesthetic throat spray, you won’t be able to eat or drink until it wears off. This usually takes around an hour. After that you can eat normally.

Before you leave the hospital, you’ll be given advice about your recovery. This will include what to do if you have any problems. It’s OK to ask questions if you have any concerns.

Your doctor or specialist nurse may explain the findings of your gastroscopy to you before you leave. You may find it best to have a friend or family member there to listen too. For example if you had a sedative, because it can affect your memory.

Ask your doctor or specialist nurse how and when you’ll get your results. You may get a date for a follow-up appointment to discuss the findings in more detail. Your results will be sent in a letter to your GP and you should get a copy of this letter. It can take up to two weeks to get results from a biopsy, if one was taken during your gastroscopy.

Recovering from a gastroscopy

After your gastroscopy, you may have a slight sore throat. This can last for one or two days. You can eat and drink as normal from about an hour after your gastroscopy.

If you’ve had a sedative, you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours. It’s best to have a friend or relative stay with you for the first 24 hours, while you rest.

Most people have no problems after a gastroscopy. You should seek medical attention immediately if you:

  • cough up or vomit blood (which may look like coffee grounds)
  • have blood in your poo or black tar-like poo
  • have severe pain in your tummy or pain that gets worse
  • have a raised temperature
  • have problems breathing

If you have any of these symptoms, tell the doctor you see that you have recently had a gastroscopy.

What are the alternatives to a gastroscopy?

The alternative to a gastroscopy is a test called a barium swallow and meal. For this test, you drink a special liquid which coats the inside of your oesophagus and stomach and shows up on X-rays.

A barium swallow and meal gives less information than a gastroscopy and may miss problems. And it doesn’t let your doctor take a sample of any abnormal tissue they might see. If you have a gastroscopy, your doctor can take a biopsy if necessary.

You can ask your doctor whether a barium swallow and meal would be an option for you.

What are the risks of having a gastroscopy?

As with every procedure, there are some risks when having a gastroscopy.


After having a gastroscopy, you may feel bloated and have some tummy discomfort for an hour or two. And you may have a sore throat for a few days. This is normal.


Complications are problems that happen during or after a procedure. Very few people have complications from a gastroscopy.

When complications do happen, they may include the following.

  • Difficulty breathing or heart problems caused by a reaction to the sedative. This is the most likely complication. Your doctor can treat these issues with medicines.
  • Bleeding from where a biopsy is taken or a small growth removed. This may stop on its own. On very rare occasions, you may need an operation to stop the bleeding.
  • Damage or tears to your throat, oesophagus, stomach or duodenum. This is rare, but if it happens, you may need an operation to repair the damage.

Complications are more likely if you’re having a treatment during your gastroscopy.

You can ask your doctor how these risks might apply to you.

It’s quite natural to worry about gagging or choking when having a gastroscopy. But try not to worry – local anaesthesia and sedation can help you to relax and prevent this.

You’ll need to swallow the gastroscope to let it move down into your stomach. Your doctor will offer to spray a local anaesthetic on to the back of your throat, to numb the area. This will help to reduce gagging as the gastroscope passes down your throat. But most people do gag a few times.

No one will make you carry on with the gastroscopy if you decide that you want to stop. But try to remember that the whole procedure is over within a few minutes. And your medical team will do all they can to help you through it.

A gastroscopy is usually done to help find out what’s causing your symptoms. But it can also be used to give certain treatments. To do these, your doctor uses specially designed instruments. They pass these down the gastroscope to treat your oesophagus, stomach or duodenum.

Treatments you may have during a gastroscopy include the following.

  • Removal of a swallowed object (foreign body) that has become stuck.
  • Stopping bleeding, for example from an ulcer. This may be by applying clips or bands or by heat-sealing. Or your doctor may inject a substance that stops the bleeding.
  • Stretching narrowed areas of your oesophagus, stomach or duodenum with a small balloon. Your doctor may leave a small tube (stent) in place to keep the stretched area open.
  • Removing polyps (small benign growths) or other growths your doctor is concerned about.

If your doctor offers you a treatment during your endoscopy, ask them to explain what’s involved.

Yes, you can have a gastroscopy if you need one. Your doctor will only recommend you have a gastroscopy if there’s a very good reason. This means they think the benefit will outweigh any potential harms to you and your unborn baby.

Doctors aren’t certain yet, but it’s unlikely that having a gastroscopy will harm your unborn baby. But your doctor will take precautions to keep you and the baby safe.

These precautions may include:

  • waiting until you’re in your second trimester before doing the endoscopy
  • doing the procedure as quickly as possible
  • giving you the least amount of sedative possible
  • having you lie on your side so the baby doesn’t press on the blood supply to the placenta
  • checking your baby’s heart rate

If your doctor recommends you have a gastroscopy, ask them to explain why this is the best option for you. It’s your choice whether or not to go ahead after talking with your doctor.

More on this topic

Did our Gastroscopy information help you?

We’d love to hear what you think. Our short survey takes just a few minutes to complete and helps us to keep improving our health information.

This information was published by Bupa's Health Content Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals and deemed accurate on the date of review. Photos are only for illustrative purposes and do not reflect every presentation of a condition.

Any information about a treatment or procedure is generic, and does not necessarily describe that treatment or procedure as delivered by Bupa or its associated providers.

The information contained on this page and in any third party websites referred to on this page is not intended nor implied to be a substitute for professional medical advice nor is it intended to be for medical diagnosis or treatment. Third party websites are not owned or controlled by Bupa and any individual may be able to access and post messages on them. Bupa is not responsible for the content or availability of these third party websites. We do not accept advertising on this page.

  • Esophagogastroduodenoscopy. Medscape., updated March 2020
  • Endoscopy. MSD Manuals., last full review/revision June 2019
  • Upper gastrointestinal surgery. Oxford Handbook of Clinical Surgery. Oxford Medicine Online., published online March 2013
  • Gastroenterology. Oxford Handbook of Clinical Medicine. Oxford Medicine Online., published September 2017
  • Upper GI endoscopy. National Institute of Diabetes and Digestive and Kidney Diseases., published July 2017
  • Gastroscopy. Cancer Research UK., last reviewed March 2019
  • Veitch AM, Vanbiervliet G, Gershlick AH, et al. Endoscopy in patients on antiplatelet or anticoagulant therapy, including direct oral anticoagulants: British Society of Gastroenterology (BSG) and European Society of Gastrointestinal Endoscopy (ESGE) guidelines. Gut 2016; 65:374–89. doi:10.1136/gutjnl-2015-311110
  • X-ray (Radiography) – Upper GI Tract., reviewed May 2019
  • Shergill AK, Ben-Menachem T, Chandrasekhara V, et al. ASGE Standard of Practice Committee. Guidelines for endoscopy in pregnant and lactating women. Gastrointest Endosc 2012; 76:18–24. doi:10.1016/j.gie.2012.02.029
  • Ludvigsson J, Lebwohl B, Ekbom A, et al. Outcomes of pregnancies for women undergoing endoscopy while they were pregnant: a nationwide cohort study. Gastroenterology, 2017; 152(3):554–63.e9. doi:10.1053/j.gastro.2016.10.016
  • Personal communication, Dr Alistair McNair, Consultant Gastroenterologist, March 2021
The Patient Information Forum tick

Our information has been awarded the PIF tick for trustworthy health information.

Content is loading