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Gastroscopy: how it is performed, preparation and results

Reference information about EGD: indications, preparation, how the procedure is performed, sedation or local anaesthesia, what happens afterwards and when to expect results.

Doctor points at a monitor screen in a diagnostic room while a patient lies on a couch before a gastroscopy
Vitalii Kravets Author Vitalii Kravets medical editor who adapts clinical guidelines for patients
Published: October 31, 2026 · Updated: October 31, 2026 · 3 min read

Gastroscopy, or EGD (esophagogastroduodenoscopy), is an examination of the inner surface of the oesophagus, stomach and upper intestine using a thin tube with a camera inside. This test helps to find out the cause of digestive symptoms. Below is a step-by-step explanation of what the procedure involves and how to prepare for it.

Why EGD is ordered

Gastroscopy may be recommended to check the cause of digestive symptoms: indigestion (dyspepsia), difficulty swallowing, stomach pain, black and sticky stool, or vomiting blood. The procedure also makes it possible to treat certain problems of the digestive tract — for example, to widen the oesophagus, remove growths or stop bleeding. A separate indication is screening for certain types of cancer, in particular stomach and oesophageal cancer.

Preparation: step by step

After a referral, the person should receive a letter with the date and place of the procedure, instructions on when to stop eating and drinking, information about possible medications before the test and the approximate waiting time for results. Pregnancy should be reported to the hospital.

  • Usually people are asked not to eat for at least 6 hours before the procedure; sometimes small sips of water are allowed. Exact instructions are given by the doctor or clinic in the referral.
  • People are asked to bring a list of all the medicines they take.
  • The doctor's instructions apply to taking medicines the day before.

How the procedure is performed and how long it takes

Before it begins, a nurse explains how the test is done and asks questions about health and medical history. For comfort, a local anaesthetic may be offered as a spray — it numbs the back of the mouth and throat — or sedation (a calming medicine given through a thin tube in the arm). During EGD, a thin flexible tube with a camera passes through the mouth or nose, then through the throat into the stomach. A feeling of nausea may occur and passes once the tube reaches the stomach; sedation helps to reduce it. Air is pumped into the stomach — a feeling of bloating and a few burps are possible. If needed, a sample of cells (a biopsy) is taken — this is painless. The procedure should not be painful, and it can be stopped at any moment on request. The gastroscopy itself lasts 15–45 minutes, and the total time at the hospital is about 4 hours from arrival to discharge.

After the procedure

After it is over, the person is moved to a recovery room; they can go home as soon as they feel well enough — for most people this is a few hours. If sedation was used, someone must accompany them home and stay with them for 24 hours, and they must avoid alcohol, driving, operating machinery and signing important documents for 24 hours. After the numbing spray, wait an hour before eating and drinking. Mild stomach and throat pain after the procedure is considered normal and passes within a few hours. Complications are rare; possible ones include a reaction to sedation, bleeding in the stomach and infection.

Call an ambulance immediately on 103 or 112 if after gastroscopy there is repeated vomiting, vomiting blood, shortness of breath, severe stomach or chest pain, or pain that gets worse.

If there is a high temperature, a feeling of heat, cold or shivering, or if the stool is dark and black, like tar, contact the hospital where the examination was performed.

When results will be available

The doctor or nurse may explain the results before discharge from the hospital. If a sample of cells (a biopsy) was taken, there will be a wait: biopsy results may take up to 2 months, and if doctors suspect cancer — usually within 2 weeks. A follow-up appointment may be scheduled to discuss the results and possible options for help. For many people, gastroscopy finds nothing worrying, but if you are anxious about the results, it is appropriate to talk to a specialist or contact support organisations.

This material is for reference only and does not replace a doctor's consultation.

Sources

  1. Gastroscopy — NHS
  2. When to call 999 — NHS
  3. When to visit A&E — NHS

Update history

First publication.
Tags GastroscopyEsophagus

This content is for reference and does not replace a doctor's consultation. Medical disclaimer