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.
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 colonoscopy help?
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 habits (either towards more frequent / 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 large bowel conditions such as, inflammatory bowel disease, requiring follow-up.
- A previous history or follow-up of polyps (benign growths) in the large bowel which qualify for colonic surveillance.
- A previous history of colorectal cancer.
Diseases of the colon can either be ruled out or diagnosed accurately. In many cases it may be appropriate to take biopsies (small samples of tissue). These are taken using tiny forceps and are sent to the laboratory. Taking biopsies is painless and very safe. It may also be necessary for the endoscopist to remove polyps (small benign growths) from the lining of the colon.
Is there an alternative?
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 be 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 this, ask your doctor.
Standard CT scans do not identify problems in the lining of the upper Gastro-intestinal tract very well and are not really a useful test to identify or rule out most problems in this area. They can sometimes be helpful when the exclusion of a very advanced, serious problem is all that is required.
Not having a colonoscopy or an alternative test would limit your doctor’s ability to confirm the cause of your symptoms or condition. You should discuss this very carefully with your doctor. If you decide against having your procedure, then please let the administrative team know so that the valuable appointment can be given to someone else.
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 the department using the details below.
- 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 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.
It is extremely important that you follow the instructions exactly.
If these instructions are not followed your colonoscopy may fail and be a waste of time or even be cancelled.
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.
What happens on the day of the procedure?
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. A nurse will talk to you first to make sure that you understand the procedure.
If you have not already done so, you will be asked to sign your consent form, giving the endoscopist remission to perform the procedure. This is done after you have had a final chance to ask questions and the clinician performing the test has ensured that the procedure remains appropriate for you.
You will be asked to decide whether you wish your colonoscopy to be undertaken with Entonox (“gas & air”), conscious sedation or both of these.
Entonox or conscious sedation?
A colonoscopy is not a pleasant experience but usually only lasts approximately 30 minutes. You may go home yourself, return to work and drive if you do not have sedation. You may wish to leave the final decision on this, to discuss when you arrive for the test.
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.
You will not be asleep, but you will be comforted and monitored carefully throughout the procedure by the nurse.
Entonox (gas & air)
Some patients choose to have a colonoscopy without sedation. You can receive Entonox (a nitrous oxide containing gas) to breathe in through a mouthpiece during the procedure to reduce the amount of discomfort. Entonox leaves your body within a few minutes with no lasting effect.
Entonox can also be used in combination with intravenous pain relief and sedation medication.
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.
- You will then be asked to lie on your left-hand side on a couch.
- A nurse will make sure to maintain 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 check the oxygen level in your blood.
- The procedure will then be performed and you might be given more sedation, if required.
- Your blood pressure will be recorded intermittently during the procedure.
- If you want the procedure to be stopped at any time, then please discuss this with the endoscopy team. 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.
- During the examination your tummy may feel bloated and slightly uncomfortable as a small amount of gas is pumped into the 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 an examination 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 colonoscopy?
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.
Serious complications occur extremely infrequently but 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.
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 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.
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 for 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.
What happens after the procedure?
When the Colonoscopy is completed you will 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.
Outside of these times you should make contact for urgent medical advice from your GP practice, local walk-in centre or, in severe cases, by attending the Accident & Emergency department at your local hospital.
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.
If you have had sedation a responsible supervising adult should take you home by car or taxi and stay with you for at least 12 hours.
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 you adhere to the following:
- 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.
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.