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Tests & diagnostics

Gastroscopy what to expect

A step-by-step patient guide to gastroscopy (OGD) - preparation, throat spray versus sedation, and what the camera can find.

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At a glance

  • Preparation

    You fast for six hours before the test, with clear fluids allowed up to two hours; if you choose sedation you must arrange an escort home.

  • What happens during the test

    A thin flexible camera is passed through the mouth into the oesophagus, stomach and duodenum; the examination itself takes five to ten minutes and biopsies are painless.

  • Results timeline

    Visual findings are explained before you leave; biopsy results typically follow within one to two weeks.

  • Specialist follow-up

    A gastroenterologist reviews the findings and histology and advises on treatment, surveillance or discharge.

What this test is and when it is recommended

Gastroscopy is the definitive test for the upper digestive tract. It is recommended for persistent indigestion or reflux, difficulty swallowing, unexplained anaemia, upper abdominal pain and suspected ulcers or coeliac disease. As well as seeing the lining directly, the endoscopist can take biopsies, test for Helicobacter pylori and treat some findings on the spot - abilities no scan can match.

How to access it

A private gastroscopy can follow a GP referral, and many providers also offer consultant-vetted direct self-pay booking. NHS waiting lists for diagnostics are often long, while private appointments are typically available within days to around two weeks. Costs vary by provider.

Frequently asked

Common questions about Gastroscopy what to expect.

Quick, plain-English answers to what people ask us most.

  • What is a gastroscopy?

    A gastroscopy, also called an upper endoscopy, uses a thin, flexible camera passed through the mouth to examine your oesophagus, stomach, and the first part of your small intestine. It allows direct visual assessment and the ability to take small tissue samples if needed.

  • Why would a doctor order a gastroscopy?

    It's used to investigate symptoms like persistent indigestion, difficulty swallowing, unexplained weight loss, or suspected ulcers, reflux, or coeliac disease. It can also be used to take biopsies or treat certain conditions found during the procedure.

  • Do I need to prepare for it?

    You'll usually need to fast for around six hours beforehand to ensure your stomach is empty for a clear view, and your clinic will advise on any medications to pause, such as certain blood thinners. Full written instructions are given ahead of your appointment.

  • What happens during the procedure?

    A throat spray or sedation is used to make the procedure more comfortable, and the thin camera is then gently passed down your throat while you lie on your side. The procedure itself typically takes around 10 to 15 minutes.

  • Does it hurt or have risks?

    Most people find it uncomfortable rather than painful, especially with sedation or throat spray, and it's generally very safe with serious complications being rare. Your endoscopist will discuss the small risks involved, such as minor bleeding, beforehand.

  • How long do results take?

    Initial findings are often discussed straight after the procedure, while biopsy results, if taken, typically take one to two weeks to come back.

  • What do abnormal results mean, and what happens next?

    Findings can range from mild inflammation or reflux, which is common and manageable, to ulcers or other conditions needing specific treatment. Your doctor will explain what was found and agree a plan, which might include medication, dietary changes, or further monitoring.

  • How much does it cost privately, and is it available on the NHS?

    Gastroscopy is available on the NHS via GP or specialist referral, with waiting times varying depending on urgency and location. Private gastroscopy is typically available within one to two weeks, with specialist care throughout, and cost varying by provider.

  • Is it accurate and reliable?

    Gastroscopy is considered the gold standard for directly examining the upper digestive tract and taking biopsies, offering more detailed information than imaging alone. Its accuracy depends on good bowel preparation and an experienced endoscopist.

  • How do I book it privately, and how quickly can I be seen?

    You can book a private gastroscopy with an initial consultation to discuss your symptoms, with the procedure itself often arranged within one to two weeks.