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Gastroscopy – examination of the gullet and stomach

Reviewed by Sue Airey, head of clinical and care services at Bowel Cancer UK

Reviewed by Dr Alan Ogilvie, gastroenterologist

What is gastroscopy?

Getty - Gastroscopy
The endoscopist may need to put some air into the stomach to perform the examination effectively.

Gastroscopy is an examination of the inside of the gullet, stomach and duodenum. It is performed by using a thin, flexible fibre-optic instrument that is passed through the mouth and allows the doctor to see whether there is any damage to the lining of the oesophagus (gullet) or stomach, and whether there are any ulcers in the stomach or duodenum.

The GP will decide when drug treatment alone is sufficient or whether an investigation by gastroscopy at the local hospital is necessary.

The procedure is painless and is usually done under a light sedative as a day-case patient in a specialised endoscopy unit.

Occasionally, after a discussion with the endoscopist, the procedure will be performed without sedation. When sedation is used, the patient will not be able to drive or operate machinery for the rest of the day.

Anyone suffering from stomach problems should consult a doctor who will, in most cases, treat the symptoms without a major examination.

How is a gastroscopy performed?

After explaining the procedure, the endoscopist will spray the back of the throat with a local anaesthetic. This is similar to the anaesthetic used by dentists. It numbs the throat and may make it difficult to swallow.

When sedation is used, it is not a full anaesthetic and the patient will still be conscious and aware. A nurse will lie the patient on their left side and the endoscopist will then gently place the end of the instrument into the mouth and ask the patient to swallow it, which feels like swallowing a large piece of food.

The endoscopist may need to put some air into the stomach to perform the examination effectively and this can cause discomfort or even a need to belch. This is perfectly normal.

The endoscopist will closely examine the lining of the gullet, stomach and duodenum to identify the cause of the symptoms. It will take about 10 to 15 minutes.

Why is gastroscopy useful?

  • The doctor can study the mucous membrane of the stomach from the top to the bottom, and see irritation, wounds, or tumours. Gastroscopy is effective, and has now replaced the use of X-rays in many cases. It helps the doctor see any abnormalities in the gullet, the stomach and the duodenum. It is precise and safe.
  • Through the gastroscope, the doctor can take samples or photographs of the mucous membrane. The most modern gastroscopes can also show the areas in the stomach on a TV screen, so that the mucous membrane can be studied thoroughly. This can be recorded on a videotape, and used for later comparison.

Patients are often given a gastroscopic examination because of their indigestion symptoms, which can usually be treated with tablets.

Occasionally, the cause of indigestion is an ulcer and it is now known that many ulcers are due to bacterial infection in the stomach.

A biopsy (a small piece of the lining of the stomach) may be removed during an endoscopy and examined under the microscope in the laboratory to pinpoint an infection or any other abnormality.

A very small number of patients with indigestion will turn out to have cancer and, again, the diagnosis can be made accurately by biopsy. Further investigation can then be planned to ensure the most effective treatment.

Can gastroscopy be used to examine other parts of the body?

On the way down towards the stomach, gastroscopy can also be used to examine the mucous membrane of the gullet - there are several diseases with symptoms that are easily mistaken for diseases in the stomach. If this examination is performed independently it is called oesophagoscopy, after oesophagus, the medical name for the gullet.

How far can a gastroscope see?

A gastroscope can only examine the lining of the oesophagus (gullet) stomach and duodenum. It will detect conditions in those organs that are causing symptoms but will not, for example, detect gallstones or pancreatic disease.

Are there other uses for gastroscopy?

An increasing use for gastroscopy is to obtain biopsies from the top of the small bowel, mainly to rule out a condition called coeliac disease. This is usually arranged at a hospital clinic but in some areas the test may be available to local doctors.

Why doesn't my doctor just send me for an X-ray?

This is a good point. Barium meals were used for many years for the diagnosis of indigestion symptoms. However, the small disadvantages of gastroscopy - special units, day-case admission and the need for sedation - are far outweighed by the increased accuracy of diagnosis and the ability to take biopsies at gastroscopy. As a result relatively few barium meals are performed nowadays.

Is gastroscopy safe?

All procedures carry some risk but outpatient diagnostic gastroscopy is very safe. Minor complications are uncommon and major complications are very rare.

Based on a text by Dr Erik Fangel Poulsen, specialist

Last updated 13.08.2013