Colonoscopy and Gastroscopy 

Endoscopy

This leaflet describes the purpose of your procedure and what is involved for you. Please read this carefully before coming for the procedure so that you can be reassured about what will happen when you attend the Endoscopy unit.

Outpatient test – This leaflet should provide you with the all the basic information about the test.

• Some patients are referred directly for a Colonoscopy by their GP or a hospital clinician. In addition to this leaflet, you will be given the opportunity to ask any questions about the procedure.
• Other patients will have been given the opportunity to ask any questions about the procedure when attending either an outpatient clinic appointment before the test or at the hospital pre-assessment visit.

Despite this, occasionally questions about the procedure remain. If you have any major concerns before then you should contact us using the contact details at the end of this leaflet. 

In-patient test – The medical and nursing staff responsible for your care will be able to answer your questions regarding the procedure.

Bi-directional endoscopic tests 

In most cases this consists of a gastroscopy (endoscopic camera test to look at the upper gut) and a colonoscopy (endoscopic camera test to look at the large bowel). These tests can occur at the same attendance, one after another, using separate instruments.  

What is a Gastroscopy? 

A gastroscopy, also sometimes called an upper gastro-intestinal endoscopy, ‘OGD’ or simply an endoscopy, is a procedure which allows the endoscopist (person performing the gastroscopy) to pass a flexible tube down through the mouth – over the back of the tongue – to examine the gullet and or swallowing tube (Oesophagus), Stomach and part of the Duodenum (see figure 1). 

It is about as thick as your index finger.  A small amount of gas is blown into the upper gut to achieve a clear view. In some cases (and often routinely) it may be necessary to take biopsies (small samples of tissue), using tiny forceps. The samples are sent to the laboratory for analysis using a microscope. Taking biopsies is painless and very safe. 

In a small proportion of patients, usually when an abnormality is identified, it may be necessary to use devices that can inject, cauterize, snare or clip an area of the upper GI tract. These devices are passed down a tiny channel within the flexible tube and are again painless and very safe. 

What is a Colonoscopy?

A colonoscopy is a procedure which allows the endoscopist (person performing the colonoscopy) to look at the lining of the colon (large bowel). This is done by passing a long flexible tube (the thickness of your index finger) through the anus and into the bowel. Gas is blown into the colon to achieve a clear view.

Your colon is about three feet (1 Metre) long. In 3 to 4% of tests the very top end of the colon may not be reached.

How may a gastroscopy and colonoscopy help?

Gastroscopy  

This examination allows the endoscopist to obtain a very clear view and thoroughly inspect your swallowing tube (Oesophagus), Stomach and first parts of your small bowel (Duodenum). A gastroscopy is often undertaken if someone has: –

• Symptoms of indigestion – particularly if these have failed to respond to standard treatment

• Difficulty swallowing

• Persistent nausea and vomiting

• Passing black motions (melaena) or vomiting blood.

• Significant weight loss

• Follow-up for upper gastrointestinal conditions such as Barrett’s oesophagus, certain types of Stomach inflammation or a previous history of Stomach ulcers or upper gastrointestinal cancer.

A gastroscopy tells us if there is any obvious reason for your symptoms (e.g., an ulcer) and helps us to work out the best way to treat it. Disease can then be either ruled out or diagnosed accurately.

Do not be surprised if appearances are all normal because many patients have symptoms without any visible abnormality!  

Biopsies are often taken and sent to the laboratory for examination – even if no obvious abnormality is seen. These may, for example, show inflammation or infection.

Colonoscopy 

This examination allows the endoscopist to obtain a very clear and thorough inspection of your colon and take pictures of the bowel for your colonoscopy report. A colonoscopy is often undertaken when someone has: –  

• Abdominal pain

• A change in bowel habit (either towards more frequent or loose stools or towards constipation)

• Noticeable rectal bleeding

• Raised results on stool samples for microscopic blood loss (Faecal Immunochemical Test [FIT]) or inflammation (Faecal Calprotectin).

• Iron deficiency anaemia

• Known gastrointestinal conditions such as, inflammatory bowel disease, requiring follow-up

• A previous history of polyps in the large bowel which qualify for colonoscopic surveillance.

• A previous history of colorectal cancer

Diseases of the colon can either be ruled out or diagnosed accurately. As with a gastroscopy, in many cases it may be appropriate to take biopsies. It may also be necessary for the endoscopist to remove polyps (small benign growths) from the lining of the colon.

Are there any alternatives?

Gastroscopy 

Your doctor has requested a Gastroscopy because they feel this is the best way of identifying or ruling out a problem in your upper Gastro-intestinal tract. These areas can also be examined by a barium swallow & meal radiological (x-ray) test. 

• It would involve you drinking a thick milky like mixture. The outline of the Oesophagus, Stomach and Duodenum will then show up when x-ray pictures are taken of you.
• To co-operate with the test, it would be necessary for you to move position several times on the x-ray table.
• No sedation is given.
• This test has even less risk than a Gastroscopy. However, biopsies cannot be taken and so some problems such as mild inflammation and early diseases could well be missed.
• In addition, a Gastroscopy may still be needed if a barium x-ray suggests an abnormality.
• You would be exposed to a small dose of x-ray radiation.

Colonoscopy

Your colon could be examined by Computerised Tomography Colonography (CTC).

• Sometimes called ‘virtual colonoscopy’, CTC is a test that uses a CT scanner to produce 3-dimensional images of the entire bowel.
• The procedure often requires some bowel preparation using laxatives similar to a standard colonoscopy.

The major advantages of CTC are: –

• It does not require sedation.

• It is non-invasive but a thin flexible tube is placed in your bottom to insert gas into the bowel.

• The entire bowel can almost always be examined.

• Abnormal areas can be detected about as well as with traditional colonoscopy.

The major disadvantages are: –

• Polyps found cannot be removed and biopsies cannot be taken so a colonoscopy may still be needed if an abnormality is found on a CTC examination.

If you might prefer any of these tests, then please ask your doctor. 

What preparation is required?

When you get your appointment

Please review the medications you take well in advance of your procedure. If you take any of the following medications then please contact us using the contact details at the end of this document.

• Anticoagulant medications to thin the blood (Warfarin, Dabigatran, Rivaroxaban, Apixaban or Edoxaban) or anti-platelet drugs (Clopidogrel, Prasugrel or Ticagrelor). Some of these need to be stopped before endoscopic procedures and some require additional treatment if they are to be omitted.
• If you are a diabetic on treatment with tablets or insulin. Special arrangements are necessary if you need insulin.

You should expect to be given the necessary instructions about what to do with these medications in the days before your colonoscopy.  If you are not given this information, then please ask. 

It will be helpful to the endoscopy team if you bring all your medications (or at least a list of these indicating the dose and how frequently they are taken) with you when you attend for your colonoscopy. 

Prior to admission 

In order to have a good clear view of the bowel at colonoscopy it is essential that the bowel is completely empty. 

You will receive a pack of laxative preparation to take to clear the bowel and you also have to follow a special diet. 

The effect of the bowel preparation is vigorous and you will need quick access to a toilet for several hours. If you get any severe abdominal pain, contact the endoscopy unit or your doctor.

Occasionally an additional enema may be required on admission. You must keep taking any essential prescribed tablets.

Please ask if you are not certain of these arrangements.

On the day of the procedure

To allow the gastroscopy to get a clear view, the gullet, Stomach and Duodenum must be completely empty. This also makes sure that you do not vomit. 

This means that you should not have any food for at least six hours before the appointment time for the Gastroscopy. Clear fluid such as black tea, black coffee, squash or water can be taken up to two hours before the procedure.

After this time, you must remain “nil by mouth”. This includes not chewing any gum. 

What happens in the Endoscopy unit? 

Your appointment letter gives a time for you to arrive at the Endoscopy unit so that all the administrative and clinical checks can be performed before your procedure takes place. Please note that although we do our best to work to appointment times the variable nature of the procedures undertaken in the endoscopy unit mean that you may experience a delay. Please be patient and bring something to occupy yourself during this time. 

When you arrive at the endoscopy unit you will be shown to your admission area and asked to change into a gown. Please feel free to also bring a dressing gown and slippers with you. 

Throat spray for gastroscopy and Entonox for colonoscopy? 

Obviously, both a gastroscopy and colonoscopy are not pleasant experiences.  A gastroscopy can usually be expected to last no more than 10 minutes whilst a standard colonoscopy takes around 30 minutes. Procedures may take longer if significant intervention is undertaken.

If you decide not to have sedation you will be offered some anaesthetic throat spray for your gastroscopy and Entonox (“gas & air” pain control) for your colonoscopy.  

The throat spray has a bitter banana taste and is sprayed into the back of your throat before the procedure to numb the area. This numbness usually goes away after about an hour. You can receive Entonox (a nitrous oxide containing gas), to breathe in through a mouthpiece during your colonoscopy, to reduce the amount of discomfort. Entonox leaves your body within a few minutes with no lasting effects. It is usually possible for you to drive yourself home after the procedure (after a 30 minute wait) if you wish to do so.   

Both of these are also available to help with procedures, as additional measures, if you do decide to have the procedure under conscious sedation. 

You may wish to leave the final decision about sedation until after further discussion when you arrive in the endoscopy unit. However, if you choose sedation, you will need to be able to make the required arrangements before the procedure can go ahead. These requirements are outlined later in this document (discharge advice section), but the most important stipulation is that if you have sedation a responsible, supervising adult must take you home by car or accompany you in a taxi and stay with you for at least 12 hours.

Conscious sedation for gastroscopy and colonoscopy? 

If you choose to have sedation you will have a small plastic cannula inserted into a vein on your hand or arm. Medication can be given through this to make you relaxed for the procedure. 

You will be conscious and awake throughout the test and may well have some awareness and memory of the test. Giving you sedation (often with the addition of analgesia, or pain relief medication) helps to ensure that this is not a distressing experience. 

What happens in the endoscopy procedure room?

• You will be asked to confirm your name and other personal details. The endoscopy team will make sure both you and the team agree that you have attended for the correct procedure.
• You may be asked to remove any false teeth, plates, or dentures.  This is particularly the case if you do not sleep with these in place.
• If you are having throat spray, then you will be asked to open your mouth and hold your breath for about 5 seconds whilst this is sprayed into the back of your throat. This taste can be an unpleasant bitter banana taste. After a few seconds you will be asked to swallow this. The numbness in your throat that this produces will fade after about one hour. This is a strange sensation, and you may feel as if you cannot swallow. This is the desired effect due to the numbness but your ability to swallow remains intact.
• A mouth guard will be placed in your mouth to protect your teeth and gums as well as protecting the endoscope from damage.
• You will then be asked to lie on your left-hand side on a couch.
• A nurse will make sure of your comfort and dignity at all times.
• If conscious sedation has been chosen, you will be given the intravenous sedative and, or pain relief injection through the cannula in your arm.
• A small tube will be placed in your nose to provide oxygen and a clip put on your finger to continuously check the oxygen level in your blood.
• The procedure will then be performed and you may be given more sedation, if required.
• Your blood pressure will be recorded intermittently during the procedures.
• If you want either of the procedures to be stopped at any time, then please discuss this with the endoscopy team (this may require raising your arm during the gastroscopy to attract attention). The endoscopist will stop the procedure and if you are still unable to continue, they will end the procedure as soon as it is safe to do so.
• After completion of your gastroscopy the examination couch will be turned around to allow your colonoscopy to be undertaken.
• During the examination your tummy may feel bloated and slightly uncomfortable as a small amount of gas is pumped into the upper gut and bowel to allow all the folds to be fully examined. This gas quickly disperses within a few hours.  
• A number of photographs are standardly taken during these procedures and taking these does not mean that anything is wrong. Abnormalities are often also photographed to inform the doctors responsible for your care. These photographs are often added to the endoscopy report. In almost all cases you will be offered a copy of your report to take home. Separate copies will be sent to your General Practitioner and any other doctors involved in your care.

What risks are associated with endoscopic procedures? 

The endoscopy team always try to ensure that the procedure is as safe as possible. Unfortunately, even when all precautions are taken and everything is done properly complications can still happen. 

The quoted risks of complications may vary according to your particular circumstances. Your doctor will be able to indicate if your risk is higher or lower than the quoted rate.

Missed lesion 

Very occasionally lesions (abnormal areas) in the bowel may be missed. This is particularly so if the bowel preparation is poor. The endoscopist may occasionally have to organise a repeat procedure or alternative investigation if the bowel preparation is not adequate. 

Sedation 

Sedation can occasionally cause problems with breathing, heart rate and blood pressure. If any of these problems do occur, they are normally short lived but may require corrective treatment by the endoscopy team. Exceptionally, reversal of the pain relief medicine or sedation may be required. 

Serious complications occur extremely infrequently but both gastroscopy and colonoscopy can result in the development of heart problems (a heart attack where a portion of heart muscle may die), a stroke (an interruption in the blood supply to the brain causing a loss of function) or exceptionally even death with a risk of approximately 1 in 15,000 for colonoscopy and 1 in 25,000 for gastroscopy. 

Allergy

There is a small risk of an allergic reaction to the sedative drugs that are administered (or less commonly the endoscopy equipment or other chemicals and substances used within the endoscopy unit) during the procedure. The endoscopy unit is a latex free environment.

Gastroscopy 

• The risk from a straightforward examination is very small and the endoscopy team will do everything they can to keep you as comfortable and safe as possible. However, a Gastroscopy is an invasive procedure and complications can occur.
• Rare serious complications are:
  • Perforation – A small leak can be produced in the wall of the gullet, Stomach or Duodenum. This is called a perforation and the risk of this is about 1 in every 2000. If this were to happen, you would need to be admitted to hospital and it might require an operation to repair it.
  • Bleeding – There is a small risk of bleeding after obtaining biopsies from the gastrointestinal tract. Bleeding usually settles spontaneously but could require a blood transfusion or an operation in rare circumstances. This risk is about 1 in every 5000.
• It is unusual to have anything worse than a mild and brief sense of a sore throat and/or bloating.
• Damage to your teeth (including crowns and bridges), gums or lips is usually avoided by use of the mouth guard. Please alert the endoscopy team if you have loose teeth.

Colonoscopy 

• Rare serious complications are:
  • Perforation – (or tear of the lining) of the bowel has a risk of approximately 1 in every 2000 examinations. An operation is often required to repair the hole. The risk of perforation is higher with polyp removal but still much less than 1 in 100.
  • Bleeding – may occur at the site of biopsy in less than 1 in 1000 cases or polyp removal with a risk of approximately 1 for every 50 procedures where this is performed.  Such bleeding is usually minor and will either simply stop on its own or if it does not, be controlled by cauterisation, injection treatment or the use of clips. Sometimes bleeding can happen up to two weeks after polyp removal. If you take blood thinning medication, then a significant sized polyp would not normally be removed at your colonoscopy and you may need to return, at a later date, after stopping such medication for a few days. This would be discussed with you at the time.

What happens after the procedure?

When the gastroscopy and colonoscopy have been completed, you will then be transferred to the recovery area and monitored by the healthcare team until you are ready for discharge home. 

After the procedures you may have some discomfort due to gas put into the upper gut and bowel during the test. You will be encouraged to pass wind and any discomfort should disappear within a few hours. It would be unusual to have any significant pain the day after any endoscopic procedure.

If you have increasing amounts of pain, or this is severe, you should contact the endoscopy unit where your procedure was performed within opening hours – details at end of leaflet. 

If you have not had sedation you will be able to leave the endoscopy unit after about 15-30 minutes following your procedures. If you have had Entonox you will not be able to drive for 30 minutes after the procedure. It is important you do not eat or drink anything for at least one hour after any throat spray. It is best to try to slowly sip cold water initially. Other fluids can then be taken if this goes down the right way.  If this causes any coughing or spluttering, then remaining nil by mouth for a further 30 minutes before trying cold water again is advised.

Recovery after sedation is variable. You will be transferred to the recovery area with continued monitoring of your heart rate and oxygen levels. Most people are ready to leave the unit within an hour or so. Once you are able to swallow properly you will be given a drink, though this may not be possible if you are still experiencing the effects of any throat spray if this was also given. 

On discharge we will usually give you a copy of your endoscopy report and as much information as possible about any abnormality identified, combined with recommendations for your subsequent management.

Discharge advice 

For at least 24 hours following a colonoscopy under sedation (and until you have returned to your previous state of full function and co-ordination) we must insist that you do not: 

• You must not go home alone, even by taxi. You must arrange an escort.
• You must be able to arrange for someone to be with you at home to supervise you until the next morning.
• You must not drive any vehicle for 24 hours.
• It is also unsafe to operate any potentially harmful equipment or machinery and you should not sign any legal documents for the same period.
• If you were to take alcohol within the same period, it would have a more pronounced and unpredictable effect. You should avoid this.

Contact us

Patient experience

South Tees Hospitals NHS Foundation Trust would like your feedback. If you wish to share your experience about your care and treatment or on behalf of a patient, please contact The Patient Experience Department who will advise you on how best to do this.

This service is based at The James Cook University Hospital but also covers the Friarage Hospital in Northallerton, our community hospitals and community health services.

To ensure we meet your communication needs please inform the Patient Experience Department of any special requirements, for example; braille or large print.

T: 01642 835964
E: [email protected]

The James Cook University Hospital, Marton Road, Middlesbrough, TS4 3BW.
Telephone: 01642 850850

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