Decorative image


Get information on what an endoscopy is, how you might have it and what happens afterwards.

An endoscopy is a test that looks inside the body. The endoscope is a long flexible tube which has a tiny camera and light on the end of it. 

There are many types of endoscopes and the doctor uses these to look inside different parts of the body. The name of the test you have will depend on which part of the body the doctor is looking at.

Why you might have it

You are most likely to have an endoscopy to look at the inside of your:

  • food pipe (oesophagus)
  • stomach
  • duodenum which is the first part of the small bowel that attaches to the stomach
  • large bowel (colon)

This test can show what is wrong if you have abnormal bleeding, indigestion or difficulty swallowing.

A doctor or specialist nurse looks down the endoscope to see if there are any growths or other abnormal looking areas. The doctor or nurse can also take samples of any abnormal looking tissue through the endoscope

Diagram of an endoscopy

Other types of endoscopy include:

  • bronchoscopy to look inside your windpipe (trachea) and bronchi (tubes going into lungs)
  • cystoscopy to look inside your bladder
  • hysteroscopy to look inside your womb
  • colonoscopy to look inside your large bowel
  • sigmoidoscopy to look inside the lower part of your large bowel


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).

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.

Endoscopic ultrasound

Sometimes an ultrasound probe is attached to the endoscope tube. This is called an endoscopic ultrasound. Ultrasound uses sound waves to build up a picture of the area. 

This test is used to look at the wall of the oesophagus, stomach, or the gallbladder and bile duct. It might help the doctors to get a better idea of the size of a tumour and how deep it has grown into the body tissues. They may also be able to see whether nearby lymph nodes are swollen (enlarged).

After your test

You need to rest for a while after the test. If you had the throat spray, you will not be able to eat or drink for about an hour afterwards, until the local anaesthetic has worn off.

You may not remember much (if anything) about the test once you have come round if you had the sedative. You should be able to go home the same day.

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, 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 cannula)
  • after having a biopsy, you may have some bleeding this usually stops on its own, if it doesn’t you might need to go into hospital to stop the bleeding

Getting your results

You should get your results within 1 or 2 weeks.

Waiting for test results can be a very worrying time. You might have contact details for a specialist nurse and you can contact them for information if you need to. It can help to talk to a close friend or relative about how you feel.

You can also contact the Cancer Research UK nurses on freephone 0808 800 4040 for information and support. The lines are open from 9am to 5pm, Monday to Friday.

Contact the doctor who arranged the test if you haven’t heard anything after a couple of weeks.

More information

We have more information on tests, treatment and support if you have been diagnosed with cancer.

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

Information and help

Dangoor sponsorship

About Cancer generously supported by Dangoor Education since 2010.