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Gastroscopy

A gastroscopy (also known as OGD - oesophago-gastro-duodenoscopy) is an examination that allows us to look directly at the upper part of the gastrointestinal tract; the oesophagus (tube that food passes down to reach the stomach); the stomach and around the first bend of the small intestine (duodenum). 

In order to do this, a thin flexible tube called a gastroscope or endoscope, which has a light at one end, is used. It is passed through the mouth or nose, down the oesophagus and into the stomach by a specially trained doctor or nurse, called an endoscopist. The tube is thinner than your little finger. It will not get in the way of your breathing at any time, as it passes down your oesophagus and not your windpipe. 

Sometimes biopsies (small tissue samples) are taken and sent for analysis. The biopsies taken are about the size of a match head and will not cause you any pain. You may feel a slight tugging sensation. 


Will I have an anaesthetic? 

You can choose to have this procedure done either with a local anaesthetic spray to numb your throat, or with conscious sedation. This procedure is not generally offered under a general anaesthetic. Each patient will react differently and may experience different levels of drowsiness. It is different from a general anaesthetic as it does not ‘knock you out’ and you are able to respond to your doctor or nurse. This sedative can have a slightly amnesic effect. However, the sensation of gagging and retching will be felt as with anything touching the back of the throat. 


If you choose to have sedation, you must arrange for a relative or friend to take you home approximately one hour after the test. This person should be 18 years of age or older. It is recommended that someone stays with you overnight. You will not be able to drive or operate any machinery for the remainder of the day and will need to rest quietly at home. 

Why do I need a gastroscopy? 

Your doctor has recommended that you have a gastroscopy to find out the cause of your symptoms, such as: 

  • pain in the upper abdomen (tummy) 
  • difficulty swallowing 
  • recurring indigestion 
  • vomiting 
  • bleeding 
  • recurring heartburn 
  • monitoring of a longer term condition. 

It can also be used to check a previously diagnosed gastrointestinal condition. 

A gastroscopy can help to diagnose: 

  • ulcers 
  • inflammation 
  • infection 
  • the presence of helicobacter pylori (bacteria that can cause ulcers, gastritis and gastric cancer) 
  • celiac disease (inability to digest gluten) 
  • cancer. 


What are the risks? 

A gastroscopy is a safe test – serious complications are uncommon. Occasionally the gastroscope can damage the lining of the oesophagus, stomach or intestine. This can cause: 

  • bleeding
  •  infection
  • rarely, a tear in the oesophagus, stomach or intestine. 

If this happens to you, you may need to have a blood transfusion, come into hospital or have surgery to treat the problem. Your doctor or specialist nurse will discuss the possible complications with you before you sign the consent form. Very rarely damage to your teeth can be caused by biting down hard on the mouth piece needed to keep your mouth open during the procedure. 

Are there any alternatives? 

An alternative is to have a barium meal. This involves having an X-ray after drinking some barium liquid. As X-rays can’t go through barium, the outline of your stomach shows up on the X-ray picture. However, you may still need a gastroscopy if any abnormalities are found. A barium test involves radiation and is less accurate than an endoscopy. However, samples or biopsies of the gut or polyps cannot be removed during a barium test, so you may still need a gastroscopy. 

How can I prepare for a gastroscopy? 

To make sure the endoscopist performing the gastroscopy has a clear view, your stomach must be completely empty. Therefore, you must not eat or drink anything for at least six hours before the test. You may take small sips of water up to two hours before your appointment. When you arrive in the unit the receptionist will ask you to sit in the waiting area until you are seen by a nurse, who will ask you about your medical history. Please tell the nurse if you have had any reactions or allergies to other examinations in the past. 

You do not need to get changed for the procedure but we may ask you to put a gown on over your clothes to protect them. Once you are ready you will be taken to the second waiting area, signposted, ‘sub wait area.’ Your endoscopist will explain more about the procedure and answer any questions you may still have. 

If you are taking any medicines that thin your blood, such as antiplatelet medicines (for example aspirin or clopidogrel) or anticoagulant medicines (for examples warfarin or rivaroxaban), please tell your doctor or the nurse as you may need to stop them temporarily before your surgery. Also tell your doctor or nurse if you have diabetes as you may need to alter the dose of your diabetes medicines, as you will need to fast before the procedure. Further information on stopping any medicines will be given to you when you come for pre-assessment. Please ask us if you have any questions.

Please let us know if you are taking any regular medicines (including anything you buy yourself over the counter or any herbal or homeopathic medicines) and if you have any allergies to any medicines.
If you are taking medications to reduce the amount of acid produced by your stomach (e.g. Omeprazole, Esomeprazole, Lanzoprazole, Pantoprazole) you should stop taking them two weeks before the gastroscopy unless you have been told otherwise by the doctor or endoscopy nurse. You should continue to take all of your other medications as normal, unless you have been told otherwise by the doctor or endoscopy nurse. 

Giving my consent (permission) 

We want to involve you in decisions about your care and treatment. If you decide to go ahead, you will be asked to sign a consent form. This states that you agree to have the treatment and you understand what it involves. If you would like more information about our consent process, please speak to a member of staff caring for you. 

What happens during a gastroscopy? 

The test will take place in one of the procedure rooms, where a nurse will ask you to remove your shoes, loosen any constricting clothing and remove any false teeth or glasses. You will need to keep your belongings with you at all times. 

You will be given either sedation or an anaesthetic throat spray for the examination. Your endoscopist will have already have discussed with you which one you would prefer. The sedation will not put you to sleep, but will make you feel drowsy and relaxed. The anaesthetic spray will only numb your throat. If you decided to have sedation, then a small needle will be inserted into your arm or hand and you will be given an injection through this. 

You will be placed on your left side on a trolley. A nurse will stay with you throughout the examination. To keep your mouth slightly open, a mouthpiece will be placed between your teeth. The gastroscope will be gently inserted into your mouth through the mouthpiece and passed down into the stomach. If you have excess saliva in your mouth, the nurse will clear this using a sucker. The endoscopist may pass some air down the gastroscope to get a clearer view. This may make you feel slightly bloated but will not be painful. 

Sometimes a biopsy (a sample of tissue) will be taken for analysis in the laboratory. The tissue is removed through the gastroscope using tiny forceps. Very rarely this is uncomfortable, but the discomfort should pass quickly. You will most likely only feel a tugging sensation. The test usually lasts between five and fifteen minutes. When the examination is finished, the gastroscope will be removed quickly and painlessly. 

What happens after a gastroscopy? 

After the procedure you will be taken to the recovery area. If you have had sedation, you will need to rest quietly until the sedative has worn off (usually a couple of hours). The nurse will check your blood pressure and pulse and offer you some tea and biscuits. 

If you have not had sedation you will be taken to the discharge area where you will be given a copy of the test results and you will be able to leave the hospital straight afterwards. However, you will not be able to eat or drink anything until your swallow reflex returns which usually takes about 45 minutes. After this, you will be able to eat and drink as normal, unless the doctor or nurse tells you otherwise. 

If you have had sedation, you must have someone to escort you home and stay with you overnight. He/she should come with you for the appointment or be contactable by phone when you are ready to leave. 


When will I get the results? 

The doctor or specialist nurse will often be able to tell you your results before you leave the hospital. If you have had a sedative, it is a good idea to have someone with you when the results are being discussed, as you may not remember all of the details afterwards, due to the sedative. If you have had biopsies taken the results may take up to one week to become available.

What do I need to do after I go home? 

The sedation lasts longer than you may think and therefore you must not: 

  • drive or ride a bicycle 
  • operate machinery or do anything requiring skill or judgement 
  • drink alcohol 
  • take sleeping tablets 
  • go to the work 
  • make any important decisions, sign contracts or legal documents. 

You should rest at home following your procedure and should be able to carry out your normal activities 24 hours after the test. 

You should consult your GP or go straight to your nearest A&E department if you develop severe abdominal (tummy) pain, a fever or are vomiting or passing large amounts of blood after the test. (Please take your endoscopy report with you).