Gastroscopy (OGD)

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What is a gastroscopy?

A gastroscopy is an endoscopy that allows your consultant to look at the inside of your oesophagus, stomach and duodenum (the first part of the small bowel).

A gastroscopy is also known as an upper GI endoscopy (or an OGD).


What happens during a gastroscopy?

The endoscopist steers a thin flexible tube that is about as wide as a finger in through your mouth and throat, down the oesophagus, through your stomach and into the duodenum.

On the end of the endoscope is a bright light and a tiny digital camera that transmits pictures to a large screen.

The procedure is not painful but it can be uncomfortable as it stimulates the gag reflex. Many patients choose to be sedated for this reason.

How long does a gastroscopy take?
The examination usually takes less than 10 minutes, but complicated therapeutic procedures may take longer.


Why might you need a gastroscopy?

A gastroscopy can be used to investigate a range of problems including:

What should you tell us before a gastroscopy?

Tell your consultant all the medications you take, particularly any blood thinners such as clopidogrel, warfarin, or heparin), or if you are on iron tablets. Our general advice to patients having a gastroscopy is to:

  • Stop taking clopidogrel 7 days before your procedure.*
  • Stop taking iron tablets 7 days before your procedure.
  • Stop taking warfarin 5 days before your colonoscopy.*

*Please check with your GP, cardiologist or anti-coagulant clinic to see if you need replacement medication.

Tell us if you have diabetes, as your medication may need to be adjusted on the day of your colonoscopy.


How do you prepare for a gastroscopy?

  • Decide whether or not you will have sedation. Not all patients need sedation but if you do this will mean you need to be accompanied home.
  • To allow a clear view, you should not eat anything for 6 hours before your appointment. You may drink clear fluids for up to 2 hours prior to the procedure (allowing you to take prescription medicines if necessary). Do not take antacids.


What happens on the day of your gastroscopy?

Come to the endoscopy unit 30 minutes before your gastroscopy. Although we always try to perform your gastroscopy at the agreed time, sometimes there are delays so your time slot cannot be guaranteed. If there is a delay, you will be kept updated.

  • When you arrive, you will be seen by one of our nursing team, who will ask you questions about your medical history, medications and allergies.
  • You will be asked to remove any glasses, contact lenses and dentures. If you have decided to have your gastroscopy with sedation, a small plastic cannula will be inserted into a vein in your arm or hand.
  • You will be asked if you understand and accept what is planned and we will then need your written consent to go ahead.
  • A local anaesthetic may be sprayed to numb your throat, and you will be asked to lie on your left side facing the consultant.
  • If you are having sedation this will be given by injection through the cannula to make you sleepy and relaxed. A guard will be put in place to protect your teeth.
  • The endoscopist then passes the endoscope through your mouth and down your throat. The endoscope will not interfere with your breathing and will not cause any pain.
  • Small samples of tissue (biopsies) may be taken during the procedure; this is painless.

What are the risks of gastroscopy?

Gastroscopy is an extremely safe procedure. The most common minor side-effect is a sore throat, which usually settles after a couple of days. Serious complications are extremely rare during routine colonoscopy but these problems may happen:

  • A perforation in the wall of the oesophagus, stomach or intestine, for example, happens less than once in every 10,000 procedures. You are at greater risk if you have a tight narrowing (a stricture) in part of your upper digestive system. In these more complex cases, the rate of perforation rises to about 1%. If a perforation does occur, you will need to stay in hospital for observation. Only some perforations need to be repaired surgically.
  • Significant bleeding following gastroscopy is very rare, but slight bleeding often occurs at the site of a biopsy. Serious bleeding needs immediate treatment and observation in hospital. Very few patients with bleeding need surgery.


What happens after a gastroscopy?

Your throat may feel numb and slightly sore, and because of the local anaesthetic and sedation you should not attempt to eat or drink anything for at least 1 hour.

If you did not have sedation you may go home as soon after the gastroscopy as you wish.

If you have received sedation you should be able to leave when fully awake (usually about an hour), but you must be accompanied by a responsible adult. Sedation makes you sleepy but it also affects your judgement and the way you make decisions. If you have been sedated:

  • Do not drive home or drive for 24 hours.
  • Do not operate machinery.
  • Do not make any important decisions.
  • Do not drink alcohol.

You will be reviewed before going home, to check that all is well. Although your consultant may be able to discuss the endoscopic findings at the time, the results of biopsies may take up to four working days to be available.


Unwell after your gastroscopy?

Complications are rare but if you experience any of these problems, please seek medical advice and contact us urgently:

  • Severe persistent pain.
  • Light-headedness or fainting.
  • Vomiting of blood.
  • Passing of blood or black tar-like stools.


Getting more information

If you have any questions concerning your procedure, please contact the gastroenterology/hepatology team at The Physicians' Clinic

The team is available Mon – Fri 0900-1700


Tel: 020 7034 8164

Fax: 020 7034 8140

Have you experienced problems:

  • Contact your consultant directly by telephoning The Physicians' Clinic during office hours as above.
  • Out of hours, please contact your gastroenterologist directly using the information supplied after your appointment.

Contact Us

020 7034 8164

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