Step-by-step walkthrough
What to expect on the day
Step 1 of 6 · Gastroscopy
Before you arrive
You will be asked not to eat for several hours beforehand, usually six, with clear fluids allowed a little longer; your letter gives the exact times. If you take regular medicines, the clinic will have told you what to do with them today.
Worth asking: "Do my usual medicines change today?"
Gastroscopy
1. Before you arrive
You will be asked not to eat for several hours beforehand, usually six, with clear fluids allowed a little longer; your letter gives the exact times. If you take regular medicines, the clinic will have told you what to do with them today.
2. Checking in
A nurse confirms your details, allergies and fasting times, and the endoscopist explains the test and takes your consent. Nothing happens without your agreement, and questions are welcome at every point.
3. Your comfort choice
For a gastroscopy you usually choose between a local anaesthetic throat spray, staying fully awake, or light sedation through a small cannula, relaxed and often remembering little. Sedation means fasting rules, an escort home and 24 hours of no driving.
4. During the test
You lie on your left side with a soft mouthguard in place. The tube is thinner than a finger; it does not block breathing, though swallowing it feels odd and some retching is normal and expected. Air is used to open the stomach for a clear view, which can feel like bloating.
5. Samples and photos
The endoscopist photographs what they see and may take tiny painless samples (biopsies) through the scope. Taking a biopsy is routine and does not by itself mean something serious was found.
6. Recovery and results
With throat spray you can usually leave soon after a short rest, waiting for the numbness to fade before eating. With sedation you rest until you are steady, then go home with your escort. The endoscopist usually gives first findings the same day; biopsy results take longer and reach you or your referring doctor later.
Colonoscopy
1. Before you arrive
The real work happens at home: the bowel prep. Low-fibre eating in the days before, then the prep drink that empties the bowel completely. Our bowel-prep planner turns your letter's schedule into a day-by-day countdown.
2. Checking in
A nurse confirms details, checks how the prep went, and the endoscopist explains the test and takes consent. Be honest if the prep was hard or incomplete; there are sensible options either way.
3. Your comfort choice
Most people choose light sedation with a painkiller through a cannula: drowsy, relaxed, often remembering little. Some choose gas-and-air or no sedation and drive home the same day. Sedation means an escort home and 24 hours of no driving.
4. During the test
You lie on your left side; the position may change once or twice to help the camera travel. Gas gently opens the bowel for a clear view, which can feel crampy and produces entirely expected wind afterwards. Tell the team if anything is too uncomfortable; they can adjust.
5. Polyps and samples
Small growths called polyps are common and usually removed painlessly there and then through the scope, which is one of the main reasons colonoscopy prevents problems rather than just finding them. Samples go to the laboratory.
6. Recovery and results
You rest while the sedation fades, get told the first findings, and go home with your escort. Expect wind and mild cramping for a day; eat gently and drink well. Laboratory results on any polyps or biopsies follow later through the clinic or your doctor.
Reviewed against NHS gastroscopy and colonoscopy information and RCoA sedation guidance.
Sources
- Gastroscopy NHS, 2023
- Colonoscopy: what happens NHS, 2023
- Sedation explained Royal College of Anaesthetists (RCoA), 2021
Last reviewed: 2026-07-16
Preparing for a colonoscopy? Build your bowel-prep countdown. Already done? Know what is normal afterwards.