Anaesthesia and sedation for endoscopy or colonoscopy

What are the anaesthesia and sedation options for endoscopy or colonoscopy?

Endoscopy means looking inside the body with a thin, flexible camera. A gastroscopy looks at the gullet, stomach and the first part of the bowel through the mouth; a colonoscopy looks at the large bowel through the back passage. These tests are uncomfortable rather than usually painful, so different comfort options are offered.

For a gastroscopy you can often choose a numbing throat spray (and stay fully alert) or sedation. For a colonoscopy, options include inhaled gas (Entonox, or 'gas and air'), sedation with a painkiller, or sometimes nothing at all. The choice affects how alert you are, how much you remember, and how you get home.

Sedation here is usually 'conscious sedation' — you feel relaxed and drowsy but are not fully asleep, and you can still respond. It is given and monitored by the endoscopy team. A general anaesthetic is only occasionally needed.

The comfort choice does not change what the test can find. It is about making the test bearable while keeping you safe, and what suits one person may not suit another.

Types, options & approaches

There may be different ways to do this. The right approach depends on the clinical question and your circumstances.

Throat spray / gas vs conscious sedation

Neither option changes what the test can find. The best choice depends on the test, your anxiety, and how you want to get home.

Preparing for your treatment

• Follow the bowel-preparation instructions exactly for a colonoscopy, and the fasting instructions for a gastroscopy — usually no solid food for several hours beforehand.
• Tell the team about all your medicines, especially blood thinners and diabetes medicines, which may need adjusting.
• Tell the team if you take a GLP-1 or 'GIP' weight-loss or diabetes medicine — such as the injections Ozempic, Wegovy, Mounjaro or Saxenda, or the tablet Rybelsus — including any bought privately. These medicines slow how quickly the stomach empties, so some food or fluid can remain even after the usual fasting time, which matters most for deeper sedation or a general anaesthetic. Do not stop them on your own; the team will decide with you whether any change is needed.
• Mention any heart, lung or breathing problems, sleep apnoea, glaucoma or recent eye or brain surgery (some affect whether gas can be used).
• Decide in advance which comfort option you would prefer, and discuss it with the team.
• If you choose sedation, arrange a responsible adult to take you home and stay with you, and plan 24 hours off driving and important decisions.
• If you choose throat spray or gas only, you can usually drive yourself home after a short wait — check this with the team.
• Bring a list of your medicines and any previous endoscopy reports.

What happens

You will be asked to confirm your details and consent, and the team will check which comfort option you have chosen. If you are having sedation or gas, a small tube (cannula) may be placed in a vein, and monitoring is attached to check your heart rate, blood pressure and oxygen.

For a gastroscopy, the throat is numbed or sedation is given, and the thin camera is passed through the mouth. For a colonoscopy, gas, sedation or nothing is used while the camera is passed through the back passage; air or carbon dioxide is used to open up the bowel, which can feel like wind or cramping.

Throughout, a member of the team watches you closely. If samples (biopsies) are taken or small growths (polyps) removed, you usually will not feel this. The test itself often takes 15–45 minutes.

Afterwards you recover in a monitored area. If you had only throat spray or gas, you can usually leave and drive after a short wait. If you had sedation, you stay until the main effects wear off and leave with a responsible adult.

Is this treatment right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

Comfort, sedation or contrast choices

If local anaesthetic, sedation, contrast or pain relief is used, ask what is planned, why, and what it means afterwards.

There are two kinds of risk to keep separate: risks from the sedation (mainly slowed breathing, which is why monitoring matters) and risks from the test itself, such as bleeding or a tear in the gut wall. Tell the team about blood thinners, breathing or heart problems and sleep apnoea. Also tell them about any GLP-1 or GIP weight-loss or diabetes injection (such as Ozempic, Wegovy or Mounjaro), as these can leave food in the stomach despite fasting and slightly raise the risk of stomach contents reaching the lungs during deeper sedation or a general anaesthetic. Ask which comfort option suits you, who will monitor you, and what the specific risks are if polyps are likely to be removed.

Published figures to discuss

It helps to separate sedation risk from the risk of the test itself. Sedation-related problems are usually temporary dips in breathing or oxygen that the team recognises and treats. Complications of the test, such as bleeding or perforation, are uncommon for a diagnostic test but rise when polyps are removed. Reported rates vary by unit, the procedure and the patient, so treat figures cautiously.

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

What happens afterwards

How you recover depends on the comfort option. With throat spray or gas you are usually back to normal quickly. With sedation, the medicine can affect your judgement and reactions for up to 24 hours even when you feel fine.

• Bloating, wind or mild cramping for a few hours
• A mild sore throat after a gastroscopy
• Feeling drowsy for the rest of the day after sedation
• Not remembering parts of the test after sedation
• A small amount of blood after a biopsy or polyp removal can occur — heavy bleeding is not normal

Aftercare

• If you had sedation, have a responsible adult take you home and stay with you.
• Rest for the remainder of the day and avoid important decisions if sedated.
• Do not drive, drink alcohol or operate machinery for 24 hours after sedation.
• Pass wind freely to relieve bloating; gentle walking can help.
• Eat lightly at first, then return to your normal diet as comfortable.
• Restart any paused medicines (such as blood thinners) only when advised.
• Watch for warning signs of bleeding or a tear (see below).
• Keep any follow-up appointment for biopsy or polyp results.

• Bowel prep or fasting instructions followed exactly
• Responsible adult booked if having sedation
• Plan for medicines such as blood thinners agreed with the team
• Day off and 24 hours with no driving if sedated
• List of medicines and previous reports brought along
• Clinic's contact number saved
• Light food and drinks ready at home

⚠ Get urgent help if…

• Severe or worsening tummy pain after the test
• A hard, swollen or very tender abdomen
• Vomiting blood or material that looks like coffee grounds
• Passing a lot of blood from the back passage, or black tarry stools
• A high temperature, chills or feeling very unwell
• Difficulty breathing, chest pain or blue lips
• Severe persistent drowsiness you cannot be roused from after sedation

Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your specialist gives you.

Results & realistic expectations

The comfort option does not change what the test can find — it is about keeping you comfortable and safe. The endoscopist can often tell you what they saw on the day, but anything sent to the laboratory (biopsies) takes longer.

A normal-looking test is reassuring but does not rule out every condition, and sometimes a repeat or further test is needed if the view was limited (for example by incomplete bowel preparation). Your team will explain what the findings mean and what happens next.

Related tests, treatments or support

Sedation or comfort options are used alongside the endoscopy itself, and the same visit often includes taking biopsies or removing polyps. A gastroscopy and colonoscopy are sometimes done in the same appointment, in which case the comfort plan covers both.

Follow-up & long-term care

You should be given written aftercare advice and a contact number before leaving. Biopsy and polyp results usually follow within one to a few weeks, by letter or at a follow-up appointment, and the team should tell you when and how to expect them and what any repeat or surveillance test would involve.

Repeat, follow-on and what comes next

• A repeat test is sometimes needed if the view was limited by poor bowel preparation or discomfort.
• Sedation may need topping up, or occasionally the test cannot be completed and is rebooked.
• Surveillance colonoscopies may be recommended at intervals if polyps or other findings are found.
• If sedation was poorly tolerated, this should be recorded to plan future tests.

Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.

What good aftercare looks like

• Continuous monitoring during the test by a trained member of the team.
• A monitored recovery period until you are stable and able to drink.
• Clear written aftercare advice, warning signs and a contact number.
• Discharge after sedation only with a responsible adult.
• A clear plan and timescale for biopsy or polyp results and any surveillance.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

• Whether sedation, gas or throat spray is used, and who provides it
• The type of endoscopy (gastroscopy, colonoscopy or both)
• The facility or day-case fee and recovery monitoring
• Whether biopsies are taken or polyps removed
• Laboratory fees for analysing any samples
• Follow-up consultation and how results are shared
• Bowel-preparation medicines for a colonoscopy

• The endoscopist's fee and the comfort/sedation option included
• The facility or day-case fee and recovery care
• Cost of biopsies, polyp removal and laboratory analysis
• Follow-up appointment and how results are shared
• What happens, and any extra cost, if a repeat test is needed
• What happens if a complication occurs and needs treatment
• The cancellation policy

On the NHS? Endoscopy with sedation or other comfort options is widely available on the NHS when clinically indicated; private endoscopy may be chosen for faster access or more choice over timing.

You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.

Consent traps and marketing red flags

These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.

Choosing a specialist safely

• Check the specialist is on the GMC Specialist Register for this area.
• Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
• You're entitled to time to consider and to have your questions answered before you agree — the specialist who looks after you should explain it, not a salesperson.
• Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
• You're entitled to your total cost in writing — including any follow-up — before you decide.

How Vuemedics verifies every consultant →

Take this to your consultation. A good specialist will welcome every one of these.

• Which comfort options can I choose for my test, and what are the trade-offs?
• If I have sedation, who will monitor me and how long will recovery take?
• Can I drive home, or do I need someone to collect me?
• Should I stop my blood thinners or diabetes medicines, and when can I restart them?
• Are polyps likely to be removed, and does that change the risks?
• When and how will I get my biopsy results, and might I need a repeat test?
• Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
• Will you be the specialist who carries out my treatment, and who looks after me afterwards?
• What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
• What does a realistic result look like — and what can this treatment not achieve?
• What are my options, including waiting, doing nothing for now, or choosing a different approach?
• Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
• What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Find a verified specialist for anaesthesia and sedation for endoscopy or colonoscopy

Every consultant is GMC-checked and independently reviewed. Search by postcode and distance, or switch to a map. Ordered by rating, relevance and recency — never by who pays.

How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: BSG — Guidelines on sedation in gastrointestinal endoscopy (2023) RCoA — Sedation explained (patient leaflet) NHS — Colonoscopy NHS — Gastroscopy RCoA — Anaesthesia and risk MHRA — GLP-1/GIP receptor agonists: risk of pulmonary aspiration during general anaesthesia or deep sedation

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.