Gastroscopy involves inserting a thin flexible tube (endoscope) into the mouth. It travels down the oesophagus, and into the stomach and first part of the small intestine (duodenum), to view these organs.
The endoscope contains a light and video camera that transmits images to a monitor, where they can be seen by a doctor.
Gastroscopy is usually done to investigate symptoms associated with the upper digestive tract - the oesophagus, the stomach and the duodenum - such as indigestion, nausea, or difficulty swallowing. It can show if there is inflammation, an ulcer or a polyp or other growth.
Sometimes gastroscopy is performed to treat conditions, such as bleeding ulcers, or to widen a narrow oesophagus, or remove a foreign body. Doctors can take biopsies of anything unusual they see, and can remove polyps.
If you are having a gastroscopy, you will need to have an empty stomach so the doctor can see clearly and so you don't vomit. You should not eat or drink for 6 hours beforehand - your doctor will advise you about the specific details before the procedure. You should also discuss with your doctor when to take any regular medications, and if you have any allergies or other medical conditions.
How to prepare for a gastroscopy
If you are having a gastroscopy, you will usually have a light sedation. It usually takes 15-30 minutes. You may feel drowsy, and you might feel bloated from air introduced during the examination. You will probably not remember anything about the procedure.
You are usually allowed to eat and drink after the procedure, but you should not drive, travel alone on public transport, operate machinery, sign legal documents, or drink alcohol for the next 24 hours. You should have a friend or relative take you home. You may need to make an appointment with your doctor to discuss the results of your examination or any biopsy results.
Is gastroscopy safe?
Gastroscopy is a safe procedure and serious complications are rare.
Complications can occasionally happen when the gastroscopy involves a surgical procedure such as the removal of polyps, or a biopsy. Bleeding may occur if a blood vessel is accidentally damaged, or the lining of the digestive tract is torn. Such damage may need further surgery to repair.
If you have any concerning symptoms after the gastroscopy - such as fever or worsening pain, contact your doctor or the hospital straight away.
Last reviewed: February 2017