Gastroscopy - How a gastroscopy is performed

Instructions about how to prepare for a gastroscopy should be included with your appointment letter.

Phone the hospital if there's anything you're unsure about.

Preparing for a gastroscopy

If you're referred for a gastroscopy, you'll need to stop taking any prescribed medicines for indigestion at least two weeks beforehand. This is because medication can mask some of the problems that a gastroscopy could find. You can continue to take antacids up until your endoscopy.

If you're taking any of the following medications, you should phone the endoscopy unit before your appointment because special arrangements may need to be made:

• any medication that's used to treat diabetes, such as insulin or metformin
• blood-thinning medication (used to prevent blood clots), such as low-dose aspirin, warfarin or clopidogrel

Don't wear nail polish on the day of your appointment because it can interfere with a device that's attached to your finger to monitor your oxygen levels.

It's important that your stomach is empty so that the whole area can be seen clearly. You'll be asked not to eat or drink anything for at least four hours before having a gastroscopy.

The procedure

A gastroscopy can take about 15 minutes, depending on why it's being carried out.

The procedure will usually be carried out by a nurse and an endoscopist (a healthcare professional who specialises in performing endoscopies). You'll meet the nurse before the procedure and they'll be able to answer any questions you have.

You should remove any glasses, contact lenses and false teeth. A nurse may then spray your throat with a local anaesthetic spray and insert a small plastic mouth guard to protect your teeth.

You'll be asked to lie down on your left-hand side and the nurse will attach a small probe to your finger. This measures your oxygen level and heart rate.

At this point, you'll usually be given an injection of sedatives into your arm. This will make you feel very drowsy so that you'll be mostly unaware of the procedure and will probably have no memory of it. However, you'll still be able to follow the instructions of the endoscopist or nurse.

The endoscopist will insert the endoscope into your throat and tell you to swallow it to help move it down into your oesophagus.

Diagnosing a condition

If the gastroscopy is being used to diagnose a certain condition, air will be blown into your stomach once the endoscope is inside. This allows the endoscopist to see any patches of redness, holes, lumps, blockages or other abnormalities.

If abnormalities are detected, a biopsy (tissue sample) can be taken and sent to a laboratory for closer examination under a microscope. You won't feel anything during a biopsy.

Treating bleeding varices

If you have bleeding varices (enlarged veins), the endoscopist will use the endoscope to locate the site of the bleeding.

If the bleeding varices are in your oesophagus, they can usually be treated using a technique called band ligation. This involves passing a small rubber band down the endoscope, which is used to seal the base of the varices and cut off the blood supply to prevent further bleeding.

If the bleeding varices are in your stomach, the site of the bleeding will be injected with a chemical called cyanoacrylate. Cyanoacrylate is the active ingredient used in superglue. It's also very useful in sealing holes or tears in body tissue.

Treating bleeding ulcers

If you have bleeding ulcers, a number of techniques may be used to treat them. For example:

• a probe may be passed through the endoscope to apply heat or small clips to stop the bleeding
• a weak solution of adrenaline may be injected around the ulcer to activate the clotting process, narrow the arteries and enhance blood clotting

During these procedures you may also receive an injection of a fast-acting acid-reducing medication, known as a proton-pump inhibitor, to prevent bleeding re-ocurring.

Narrowed oesophagus

If you have a narrowed oesophagus, the endoscopist can pass instruments down the endoscope to help stretch and widen it. The instruments can also be used to insert a rigid balloon or stent (a hollow plastic or metal tube) to hold the walls of your oesophagus open.

Recovery

You'll usually be sedated during a gastroscopy, so you'll be very drowsy both during and after the procedure.

After the procedure, the endoscope will be removed and you'll be taken to a recovery room until the effects of the sedation have worn off.

If your gastroscopy was part of a treatment, you may be given a series of tests to assess how effective the treatment was and check for any complications. The tests may include a:

• chest X-ray
• measure of your heart rate
• blood pressure test

Depending on your individual circumstances, you'll then either be transferred to a hospital ward or discharged (sent home).

If you're discharged, you should arrange for someone to take you home and to stay with you for at least 12 hours after having the procedure.

Even if you feel very alert, the sedative can stay in your blood for 24 hours and you may experience further episodes of drowsiness. 

You therefore shouldn't drive, operate heavy machinery, or drink alcohol during this time.

Depending on the type of gastroscopy you have had, it may be several days before you can resume a normal diet. The endoscopy nurse will give you more information about your specific dietary recommendations.

Results

If you've had a gastroscopy to diagnose a condition, a further appointment may be made so you can discuss the results with the doctor in charge of your care. Alternatively, the results may be sent to your GP.