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Find out what an endoscopy is, how you have it and what happens after it.

An endoscopy is a test to look inside your body. Doctors can use it to diagnose oesophageal cancer.

This information is about having an endoscopy of the oesophagus, stomach or small bowel (duodenum). This is also called a gastroscopy or oesophagho gastric duodenoscopy (OGD).

The doctor uses a long flexible tube (endoscope) with a tiny camera and light on the end to look inside your oesophagus. They check the oesophagus for growths or abnormal looking areas.

They can also take samples (biopsies) of any abnormal looking tissues and send them to the laboratory to examine under a microscope.

Diagram of an endoscopy

Preparing for your test

You might have a blood test 2 days beforehand to check how well your blood clots.

Tell your doctor if you're taking medicine that changes how your blood clots. This includes:

  • aspirin
  • clopidogrel
  • arthritis medicines
  • warfarin

Your doctor tells you if you need to stop taking any other medicines.

You can't eat for 6 to 8 hours before the test but you might be able to drink sips of water up to 2 hours before your appointment. Your doctor or nurse gives you written instructions about this beforehand.

Talk to your doctor if not eating could be a problem for you. For example, if you have diabetes.

What happens

Most people have an endoscopy as an outpatient. A nurse will be there when you have the test. A doctor or a specialist nurse (endoscopist) will do the test. 

When you arrive at the clinic they may ask you to take your upper clothing off and put on a hospital gown. 

You can usually have the test while you're awake but you can choose to have a medicine to make you drowsy (a sedative).

This animation shows how you have an endoscopy, it lasts for 1 minute 19 seconds.

Having the test awake

Your doctor or nurse will spray the back of your throat to numb it and make it easier to swallow the tube. You then lie on your side.

It takes a few minutes for your throat to go numb. Then the endoscopist passes the endoscope tube into your mouth and down your throat to the oesophagus. The tube is slightly bigger than a pen and will be uncomfortable but shouldn’t be painful.

The endoscopist will ask you to swallow as the tube goes down. They put a small amount of air into the tube to help them see your oesophagus, stomach and first part of your bowel if they need to.

Having the test while drowsy

You lie down on the couch and then have an injection of the sedative. It takes a few minutes for you to get sleepy.

Then the endoscopist passes the endoscopy tube down your throat.

During the test they might ultrasound the wall of your oesophagus by attaching a probe inside the endoscope. The probe uses sound waves to build up a picture so they can measure any tumour and see how deeply it's grown into the tissues. They may also be able to see whether nearby lymph nodes are swollen (enlarged).

After your test

The doctor removes the tube. You will need to rest for a while. You might need to stay in the department for a few hours.

If you've had a sedative, you might not remember much (if anything) about the test once you have come round.

You should be able to go home the same day. You will need to take someone with you to the hospital appointment. You won't be able to drive for the rest of the day and should have someone to go home with you and stay overnight.

Getting your results

You should get your results within 1 to 2 weeks. The doctor who arranged your endoscopy will give them to you. 

Waiting for results can make you anxious. You can ask your doctor or nurse how long it will take to get the results. Contact the doctor who arranged the test if you haven't heard anything after a couple of weeks.

Possible risks

Endoscopy is a very safe procedure but your nurse will tell you who to contact if you have any problems after your endoscopy.

Your doctors will make sure the benefits of having an endoscopy outweigh the possible risks.

Risks include
  • bloating and discomfort lasting a few hours
  • a sore throat that can last for up to 24 hours – contact the hospital if you have severe pain in your throat, chest or tummy (abdomen)
  • fluid going into your lungs from your mouth – this is a small risk if you have a sedative but your nurse will remove most of the secretions from your mouth during the test to reduce this risk
  • a reaction to the sedative causing breathing difficulties – your nurse will check your oxygen levels during the test and you'll have oxygen through a tube that fits into your nose (nasal cannulae)

If cancer is found

If cancer is found, you'll go on to have further tests.

Last reviewed: 
28 Oct 2016
  • The Royal Marsden Manual of Clinical Nursing Procedures
    9th,Professional Edition L Dougherty and S Lister (Editors) (Royal Marsden Manual Series) Wiley-Blackwell, 2015

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