logo

Patient Information

Gastroscopy and colonoscopy

https://kingstonhospital.nhs.uk/information/gastroscopy-and-colonoscopy

Read this information as soon as your doctor has recommended a gastroscopy and colonoscopy. It covers what you need to know beforehand. It includes essential information about the procedures and how to prepare for them. You may need to start preparing 14 days beforehand.

If you read this information and decide you do not wish to go ahead, or want to consider alternatives, discuss this with your GP or hospital doctor. Do this as soon as possible before your appointment. 

Key messages

1. Contact the nurse helpline now: 

• if you are pregnant, or may be pregnant
• if you have a pacemaker
• if you have an implantable heart defibrillator
• if you take any medicine to help prevent clots, such as warfarin, rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Lixiana) or dabigatran (Pradaxa) 
• if you have a stoma.

2. Check the list of medicines to see if you need to change yours beforehand

Look at Medicines when having an endoscopy for details of which medicines must be stopped or changed before a colonoscopy.
https://kingstonhospital.nhs.uk/information/medicines-when-having-an-endoscopy/.

3. Carefully read the bowel preparation instructions

Look at the instructions for bowel preparation we have also sent you. This must be started 3 to 7 days before the procedure. Your colonoscopy may not go ahead if you have not completed the bowel preparation as instructed.

4. If you have diabetes, check the separate instructions carefully

Look at Diabetes and having an endoscopy with bowel preparation if you have diabetes:
https://kingstonhospital.nhs.uk/information/diabetes-and-having-an-endoscopy-with-bowel-preparation/

5. Plan how you will get home

During the procedure, you may have medicines to relax you and relieve pain. If so, you must arrange to have a responsible adult to take you home and stay with you for 24 hours. During this time, you will not be able to, for example, drive, use the oven or kettle, go back to work or look after small children. 

What are a gastroscopy and colonoscopy?

A gastroscopy is a procedure to look at the inside of your oesophagus (gullet), stomach and duodenum (beginning of your small bowel) using a flexible endoscope (camera).

A colonoscopy is a procedure to look at the inside of your large bowel (colon) using a flexible endoscope.

Shared decision making and informed consent

Your healthcare team have suggested a gastroscopy and colonoscopy. However, it is your decision to go ahead with the procedure or not. This document will give you information about the benefits and risks to help you make an informed decision.

Shared decision making happens when you decide on your treatment together with your healthcare team. Giving your ‘informed consent’’ means choosing to go ahead with the procedure having understood the benefits, risks, alternatives and what will happen if you decide not to have it. If you have any questions that this document does not answer, it is important to ask your healthcare team.

Once all your questions have been answered and you feel ready to go ahead with the procedure, you will be asked to sign the informed consent form. This is the final step in the decision-making process. However, you can still change your mind at any point.

What are the benefits?

Your doctor is concerned that you may have a problem in your digestive system. They may have recommended a gastroscopy and colonoscopy because you have been experiencing symptoms such as stomach pain, difficulty swallowing, bloating, diarrhoea and/or unexplained weight loss. Another reason might be that you do not have symptoms, but you are anaemic. This procedure is a good way of diagnosing most problems with your digestive system.

If the endoscopist (the person doing the procedures) finds a problem, they can perform biopsies (removing small pieces of tissue) to help make the diagnosis.

Sometimes a polyp (small growth) is the cause of the problem and the endoscopist may be able to remove it during the procedure.

Are there any alternatives?

Your healthcare team have suggested a gastroscopy and colonoscopy as it a good way to help diagnosing most problems with your digestive system.

A barium meal is an x-ray test of your upper digestive system. This test is not as accurate as a gastroscopy. Alternatives to a colonoscopy include a CT colography (a CT scan of your large bowel).

If your doctor finds a problem, you may still need a gastroscopy or colonoscopy to treat the problem or perform biopsies.

What will happen if I decide not to have the procedure or the procedure is delayed?

Your healthcare team may not be able to confirm what is causing your symptoms, and they may get worse. If they do, you should speak to your healthcare team.

If you decide not to proceed, you should discuss this carefully with your healthcare team.

Before the procedure

If you have diabetes, let the healthcare team know as soon as possible. You will need special advice depending on the treatment you receive for your diabetes.

Look at Diabetes and having an endoscopy with bowel preparation if you have diabetes:
https://kingstonhospital.nhs.uk/information/diabetes-and-having-an-endoscopy-with-bowel-preparation/

Medication

If you take warfarin, clopidogrel or other blood-thinning medication or are diabetic, let your healthcare team know at least 10 days before the procedure. If you are diabetic, you will need special advice depending on the treatment you receive for your diabetes.

If you take iron tablets, stop taking them at least 7 days before the procedure.

If you can, stop taking loperamide and codeine for 3 days before the procedure.

Look at Medicines when having an endoscopy for more details of which medicines must be stopped or changed before a colonoscopy.
https://kingstonhospital.nhs.uk/information/medicines-when-having-an-endoscopy/.

Preparation

Look at the instructions for bowel preparation we have also sent you. This must be started 3 to 7 days before the procedure. Your colonoscopy may not go ahead if you have not completed the bowel preparation as instructed.

You will need to follow a special diet and should be given information about this before the procedure. You will be given strong laxatives to take before the procedure. This is to make sure your large bowel is empty so the endoscopist can have a clear view. Laxatives can make you dehydrated, so drink plenty of fluids before the procedure. If you cannot drink fluids, have severe abdominal pain or continuously vomit, speak to your healthcare team. You may have a higher risk of dehydration or too much fluid if you are already dehydrated, older or are taking large doses of diuretics (water tablets) for heart or kidney disease.

Laxatives can affect how well your body absorbs medication. Do not take medication orally (by mouth) within one hour of taking the laxatives. If you are unsure of anything, speak to your healthcare team.

When you arrive

We try to see you close to your appointment time. However, this may not always be possible. We will tell you of any significant delays. Please allow up to 3 hours in total for your visit. 

We will be happy to answer any questions when you come in. Please ask if you wish to discuss anything in private. 

The healthcare team will carry out a number of checks to make sure you have the procedure you came in for. You can help by confirming your name and the procedure you are having with your healthcare team.

The healthcare team will ask you to sign the consent form once you have read this  document and they have answered your questions. You will be asked to confirm your consent on the day of the procedure.

What does the procedure involve?

A gastroscopy and colonoscopy usually takes about 1 hour.

The endoscopist may offer you a sedative or painkiller to help you to relax. They will give it to you through a small needle in your arm or the back of your hand. You will be able to ask and answer questions but you will feel relaxed. You may not be aware of or remember the procedure. The healthcare team can give you more information about this.

In rare cases your endoscopist may perform the procedure with you asleep under a general anaesthetic. They can give you this through the small needle, or as a mixture of anaesthetic gas that you breathe through a tube which passes into your airways. This means you will be unaware of the procedure. There are complications associated with a general anaesthetic. The healthcare team can give you more information.

Once you have removed any false teeth or plates, they may spray your throat with some local anaesthetic and ask you to swallow it. This can taste unpleasant.

The endoscopist will ask you to lie on your left side and will place a plastic mouthpiece in your mouth. The healthcare team will monitor your oxygen levels and heart rate using a finger or toe clip. If you need oxygen, they will give it to you through a mask or small tube under your nostrils.

If you are awake during the procedure and at any time you want it to stop, let the endoscopist know. The endoscopist will end the procedure as soon as it is safe to do so.

A gastroscopy involves placing a flexible telescope (endoscope) into the back of your throat. The endoscopist may ask you to swallow when the endoscope is in your throat. This will help the endoscope to pass easily into your oesophagus and down into your stomach. From here the endoscope will pass into your duodenum.

A colonoscopy involves placing a flexible telescope into your back passage and blowing some air into your large bowel to get a clear view.

The endoscopist will be able to look for problems such as inflammation, ulcers or polyps (small growths). They will be able to perform biopsies and take photographs to help make the diagnosis. If they find a polyp, it may be possible to remove it during the procedure.

What complications can happen?

The healthcare team are trained to reduce the risk of complications.

Any risk rates given are taken from studies of people who have had this procedure. Your healthcare team may be able to tell you if the risk of a complication is higher or lower for you.

Possible complications of this procedure are shown below from most to least likely. Some can be serious. Rarely, you may need to come back into hospital for more treatment, including surgery.

Ask your healthcare team if there is anything you do not understand.

Common
More than 1 in 20
Pain during and after the procedure
You may have pain or discomfort during and following the procedure. Pain relief options will be discussed with you.
During the procedure, harmless gas is passed into the bowel to open it up so that it can be seen clearly. This can cause some bloating or a cramping feeling. If you feel pain, let the colonoscopist know. They can change what they are doing to make you as comfortable as possible.

Sore or dry throat

Bleeding from your bottom
Rectal bleeding is the medical term for bleeding from the bottom (rectum). A small amount of bleeding is common after the procedure if a tissue sample has been taken or a polyp has been removed. This should settle without any treatment. It is rare to experience a significant amount of rectal bleeding. The risk may be higher for patients with a bleeding condition or on blood thinning medications.

Procedure not completed
It may not be possible to complete the procedure as planned:
•  if the bowel preparation has not been effective
•  if you find it too painful
•  if the procedure is technically too difficult.
We may recommend a repeat procedure or an alternative investigation.
Less common
Up to 1 in 20
Complications of sedation
Sedation medicines can cause:
•  blood pressure to drop, or the rate of breathing to fall. You will be closely monitored throughout and the team will respond to any changes in these
•  nausea and vomiting
•  unsteadiness on your feet
•  affect on memory and judgement for up to 24 hours. So it is important to have an adult with you for 24 hours after the procedure, and not to drive, operate machinery or be responsible for any children
•  allergic reaction to sedation medicines are very rare.

Damage to teeth, lips or gums
This is a risk of damage to teeth, including cracks or breaks in teeth, loss of teeth, loss of crowns, fillings or bridgework, or damage to the tooth root.
It is also possible to have some bruising or cracking of the lips which can be sore for a few days.

Vomiting blood
There is a chance of vomiting blood after the procedure. This is called ‘haematemesis’ and is when the blood comes from the oesophagus or stomach. It can range from small flecks of blood to a lot of blood. In most cases, there is only a small amount of blood. If samples of tissue (biopsies) are not taken during the procedure, this bleeding is rare.

Missed abnormalities
It is possible to miss small abnormalities, particularly if the bowel preparation is not ideal.
Rare
Up to 1 in 100
Dehydration
The bowel preparation used before this procedure can cause some patients to become dehydrated, and cause salt (electrolyte) disturbances. The risk of this is higher in the elderly and in those who have existing kidney problems.

Lung infection
There is a risk of lung infection caused by contents of the stomach reaching the lung. This is called ‘aspiration pneumonia’. It is rare (around 1 in 1000 cases).

Tear in the stomach, bowel or oesophagus
There is risk of a tear or hole (called a perforation) in the oesophagus, stomach or bowel. The risk is higher if a polyp is removed, especially if it is a large polyp. This is a serious complication. It usually needs a procedure or operation to repair it. This can involve forming a stoma (your bowel opening onto your skin) if the tear is in your lower bowel.
Overall, the risk of perforation during a colonoscopy or gastroscopy is very rare (around 1 in 1,700).

Significant bleeding
Some bleeding is expected during most procedures, however significant bleeding may need further treatment. Usually it can be dealt with during the procedure, but may lead to:
•  a change from the planned procedure
•  a blood transfusion
•   further emergency treatment.
Heavy bleeding requiring blood transfusion and admission is very rare (around 1 in 2,400 cases).

Injury to the spleen
The spleen is an organ in the upper left part of the abdomen which is involved in filtering blood and fighting infection. It can be injured during the procedure. This can lead to significant bleeding. This may be spotted during the procedure or in the hours afterwards. It may need emergency treatment to stop the bleeding or remove the spleen.
Injury to the spleen is very rare (around 1 in 5000 cases). Around 1 in 20 of these patients die.

What happens after the procedure?

After the procedure you will be transferred to the recovery area where you can rest.

If you were not given a sedative, you should be able to go home after a member of the healthcare team has spoken to you and decided you are ready. If you were given a sedative, you will usually recover in about 2 hour, but this depends on how much sedative you were given.

Do not eat or drink for at least the first hour after the procedure. Once you are able to swallow properly, you will be given a drink.

You may feel a bit bloated for a few hours, but this will pass.

The healthcare team will tell you what was found during the procedure and discuss with you any treatment or follow-up you need. Results from biopsies will not be available until a later date so the healthcare team will write to you, call you or ask you to come back to the clinic to give you the results.

Before you leave, you will be given a discharge advice sheet and a copy of your procedure report. The advice sheet will explain who to contact if you have any problems after your procedure. A copy of the report will be sent to your GP and doctor.

If you had sedation:

  • if you go home the same day, a responsible adult should take you home in a car or taxi. They should stay with you for at least 24 hours unless your healthcare team tells you otherwise
  • be near a telephone in case of an emergency
  • do not drive, operate machinery or do any potentially dangerous activities (this includes cooking) for at least 24 hours and not until you have fully recovered feeling, movement and co-ordination
  • do not sign legal documents or drink alcohol for at least 24 hours.

You should be able to return to work the next day unless you are told otherwise.

Once at home, if you experience pain or symptoms that are causing concern, contact the endoscopy unit, your GP or call 111. If you have serious symptoms, like heavy bleeding from your back passage, call an ambulance or go immediately to your nearest emergency department.

Summary

A gastroscopy and colonoscopy is usually a safe and effective way of finding out if there is a problem with your digestive system. However, complications can happen. Being aware of them will help you make an informed decision about surgery. This will also help you and the healthcare team to identify and treat any problems early.

Contact us 

Endoscopy nurses helpline:

020 8934 6614 (2pm to 4pm only) 

We strongly advise you read this information carefully before calling us. The answers to your questions may already be covered. 

Call for questions relating to your procedure, medicines, or preparation for your test, which is not included in this leaflet and needs to be answered before you attend your appointment. 

Make sure you have your hospital number ready before calling together with your full name and date of birth. Have a pen and paper ready too in case you need to write down information. 

To reschedule or cancel appointments 

Endoscopy Bookings: 020 8934 2099 option 2 (9am to 5pm) or Email khn-tr.endoscopy@nhs.net 

Your appointment is valuable. If you need to change your appointment, give us as much notice as possible, preferably at least 10 days. This allows us to offer the appointment to another patient.   

Please note, the booking team cannot answer questions relating to the procedure.  

Gastroscopy and colonoscopy - Kingston Hospital Download PDF


Contacts

Endoscopy nurses helpline 020 8934 6614 (2pm to 4pm only)
Endoscopy bookings 020 8934 2099 option 2 (9am to 5pm)
khn-tr.endoscopy@nhs.net

Translate Please speak to a member of staff before or during your visit to the hospital if you require translation.
Accessibility Please contact the Patient Experience Team on 020 8934 3850 if you need this information in a different format.
For information accessibility please visit Kingston Hospital AccessAble www.accessable.co.uk/kingston-hospital-nhs-foundation-trust
Support services

Visit the hospital website, ask a member of staff, or ring us for details.

www.kingstonhospital.nhs.uk

Switchboard 020 8546 7711

  • ‘Find Us’ page for maps, transport, registering a blue badge, disabled access
  • Information, advice and support for patients and relatives (PALS) 020 8934 3993
  • Pastoral and Spiritual Support 020 8546 7711
  • Learning Disability Liaison Team 020 8934 6895
Print - Standard Size Print - Large Size

Translate

Please speak to a member of staff before or during your visit to the hospital if you require translation support to access Patient Information. Please ring the phone number on your appointment letter, if you have one.

Request More Information

Accessibility

Please contact the Patient Experience Team on 020 893 3850 if you need this information in a different format.
For detailed information on accessibility at Kingston Hospital visit Kingston Hospital AccessAble (https://www.accessable.co.uk/kingston-hospital-nhs-foundation-trust).


Tell us how we are doing we'd love to have your opinion