The procedure you will be having is
called a colonoscopy. This is an examination of your large bowel (colon). It
will be performed by, or under the supervision of, a trained doctor who will try
and make the investigation as comfortable as possible for you. When you are
having a colonoscopy procedure, you will normally be given sedation and
analgesia.
Drawing showing a doctor performing a colonoscopy on a patient.
Why do I need to have a Colonoscopy?
You may need a colonoscopy for one of
the following reasons:
- To try and find the cause for your symptoms, help with treatment, and if necessary, to decide on further investigation.
- Follow up inspection of previous disease.
- Assessing the clinical importance of an abnormality seen on an x-ray.
A Barium enema examination is an
alternative investigation. It has the disadvantage that samples of the bowel
cannot be taken if an abnormality is found. If this is the case a subsequent
colonoscopy may be required.
What is a Colonoscopy?
This test is a very accurate way of
looking at the lining of your large bowel (colon) to establish whether there is
any disease present. The test also allows us to take tissue samples (biopsies)
if necessary, for analysis by the pathology department. The instrument used in this
investigation is called a flexible colonoscope. The colonoscope directs light
onto the lining of your bowel, and pictures are relayed to a television screen.
This means the endoscopist has a clear view and can see whether or not disease or
inflammation are present.
During the investigation the
endoscopist may need to take some samples from the lining of your colon for
analysis: this is painless. The samples will be sent to the Pathology
Laboratory or, if required, to other specialist laboratories. Small samples of
tissue are usually retained indefinitely in the department as part of your
medical record. Once the diagnostic process is complete some of these samples
may be used for quality control, teaching and ethically approved research. A
video recording and / or photographs may be taken and retained as part of your
medical record. All photographs and videos are confidential.
Schematic diagram showing a colonoscope (camera) examining by direct visualization, the inside of the colon (large bowel).
Preparing for the Colonoscopy
Eating and Drinking
It is necessary to have clear views of
the lower bowel.
Two days before the appointment
- You will need to be on a low fibre diet and considerably increase your fluid intake.
One day before
- You should take clear fluids only (no solid food) e.g. glucose drinks, Bovril, black tea and coffee with sugar, clear soups and fruit jelly.
- In addition you will need to take a laxative which should have arrived with this booklet along with clear instructions on how to take it. If you have any queries do not hesitate to contact the endoscopy unit and someone will assist you.
On the day of the examination
- Please bring a dressing gown and slippers with you if you can.
- You may continue taking clear fluids until you attend for your appointment.
What about my Medication?
Routine Medication
Your routine medication should be
taken. If you are taking iron tablets you must
stop these 7 days prior to your appointment. If you are taking stool bulking
agents (e.g. Fibogel, Regulan, Proctofibe), Loperamide (Imodium) Lomotil or
Codeine Phosphate you must stop these 3 days prior to your
appointment.
Diabetics
If you are diabetic controlled on
insulin or medication, please tell the endoscopy department so that the
appointment can be made at the beginning of the list.
Anticoagulants / Allergies
If you are taking anticoagulants such
as warfarin or anti-platelet drug, clopidogrel, let the endoscopy department
and/or your doctor know. For other allergies fill in
pre-colonoscopy questionnaire (enclosed) and inform the nurse on the day.
The procedure may involve injecting you
with a muscle relaxant called Buscopan to relax your bowel and make the
procedure more comfortable. Buscopan can affect the pressure in your eyes, so
let the doctor know if you suffer from glaucoma.
How long will I be in the Endoscopy
Department?
This depends on how quickly you recover
from the sedation and how busy the department is. You should expect to be in
the department for approximately 3 hours. The department also looks after
emergencies and these may take priority over outpatient lists. We will keep you
informed if this happens.
What happens when I arrive?
When you arrive in the department, you
will be met by a qualified nurse or health care assistant and asked a few
questions, one of which concerns your arrangements for getting home. If you
have not made suitable arrangements for your transport home or care after the
investigation then we may have to re-arrange your appointment. You will be
asked to change into a gown.
The nurse will ensure you understand
the procedure and discuss any outstanding concerns or questions you may have.
As you will be having sedation a small needle may be inserted in the back of
your hand or arm through which sedation will be administered later. Following sedation you will not be
permitted to drive or use public transport, so you must arrange for a family
member or friend to collect you. The nurse will need to be given their
telephone number so they can be contacted when you are ready for discharge.
You will have a brief medical
assessment with a qualified endoscopy nurse who will ask you some questions
regarding your medical condition and any surgery or illnesses you have had to
confirm that you are fit to undergo the investigation. Your blood pressure, heart rate and
oxygen levels will be recorded. If you are diabetic your blood glucose level
will be recorded.
If you have not already done so, and
you want to proceed, you will be asked to sign your consent form.
The Colonoscopy Investigation
In the procedure room the endoscopist
and the nurses will introduce themselves and you will have the opportunity to
ask any final questions. The nurse looking after you will ask
you to lie on your left side. She will then place the oxygen monitoring probe
on your finger and a blood pressure cuff on your arm.
Intravenous Sedation
This will make you drowsy and relaxed
but not unconscious. You will be in a state called co-operative sedation. This
means that although drowsy, you will still hear what is said to you and will be
able to follow simple instructions during the investigation. Sedation makes it
unlikely that you will remember anything about the examination.
Whilst you are sedated we will monitor
your breathing, heart rate and blood pressure so changes will be noted and
dealt with accordingly. For this reason you will be connected by a finger probe
to a machine which measures your oxygen levels and heart rate during the
procedure.
Please note: As you have had sedation
you must not drive, take alcohol, operate heavy machinery or sign any legally
binding documents for 24 hours following the procedure and you will need
someone to accompany you home. The sedation drugs will be given into a
vein in your hand or arm.
The colonoscopy involves manoeuvring
the colonoscope around the entire length of your large bowel. There are some
bends that naturally occur in the bowel and negotiating these may be uncomfortable
for a short period of time. The sedation and analgesia will minimise any
discomfort. You may be asked to lie on the right side, back or stomach to aid
the test and reduce discomfort. Air is gently passed into the bowel
during the investigation to facilitate the passage of the colonoscope. During the procedure samples may be
taken from the lining of your bowel for analysis in our laboratories. These
will be retained.
Risks of the Procedure
Lower gastrointestinal endoscopy is
classed as an invasive investigation and because of that it has the possibility
of associated complications. These occur extremely infrequently; we draw
attention to them so that you can make an informed decision. The doctor who has requested the test
will have considered the risk and compared them with the benefit of having the
procedure.
The risks are associated with the procedure itself and with the
administration of sedation. The health care team will make your
procedure as safe as possible. However, complications can happen. Some of these
can be serious and very rarely cause death (1 in 15,000).
The Endoscopic Procedure
The main risks are mechanical
damage:
- Perforation (the risk is approximately 1 for every 1,000 examinations) or tear of the lining of the bowel. An operation maybe required to repair the hole. The risk of perforation is higher with polyp removal.
- Bleeding may occur at the site of the biopsy or polyp removal (the risk is approximately 1 for every 100-150 examinations where this is performed). Usually minor, this type of bleeding may either simply stop on its own or if not, be controlled by heating (cauterisation) or injecting the area.
Allergic Reaction
It is possible to have an allergic
reaction to the equipment, materials or drugs. The endoscopy team is trained to
detect and treat any reactions that might happen. Let the endoscopist know if
you have any allergies or if you have reacted to any drugs or tests in the
past.
Not being able to finish the Coloscopy
This can happen due to a technical
difficulty, blockage in the large bowel, complications during the procedure or
discomfort. Your doctor may recommend another colonoscopy or a different test,
such as a barium enema.
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. Careful monitoring by a fully
trained endoscopy nurse ensures that any potential problems can be identified
and treated rapidly.
Older patients and those who have
significant health problems (for example, people with significant breathing
difficulties due to a bad chest) may be assessed by a doctor before having the
procedure.
What is a Colon Polyp?
A polyp is a protrusion from the lining
of the bowel. Some polyps are attached to the intestinal wall by a stalk and
look like a mushroom. Others are flat without a stalk. Generally when polyps
are found they are removed or biopsied by the endoscopist as they may grow
later and cause problems. Flat polyps are generally a little more difficult to
remove.
Polypectomy
A polyp may be removed in one of two
ways, both using an electrical current known as a diathermy. For large polyps a snare (wire loop) is
placed around the polyp. A high frequency current is then applied and the polyp
is removed.
Flat polyps (without any stalk) can be
removed by a procedure called EMR (Endoscopic Mucosal Resection). This involves
injecting the lining of the bowel that surrounds the flat polyp. This raises
the area and allows the wire loop snare to capture the polyp. For smaller polyps, biopsy forceps are
used. These hold the polyp whilst diathermy is applied and destroy the polyp.
Schematic diagram showing how a polypectomy is performed, using the colonoscope.
After the Procedure
You will be allowed to rest for as long
as is necessary. You may feel a bit bloated for a few hours but this will
subside. Your blood pressure and heart rate will be recorded. If you are
diabetic your blood glucose will be monitored. Should you have underlying
breathing difficulties or if your oxygen levels were low during the procedure,
we will continue to monitor your breathing.
Once you have recovered from the
initial effects of the sedation (which normally take 30-60 minutes) you may be
moved to a chair and offered a hot drink, toast or biscuits. Before you leave
the department the nurse or endoscopist will discuss the findings and any
medication or further investigations required. You will also inform you if you
need further appointments.
Results from biopsies may not be
available for a few days. They will be either sent to your family doctor or given to you
at an outpatient appointment.
The sedation may temporarily affect
your memory so it is a good idea to have a member of your family or friend with
you when you are given this information. There will be a short written report
available. The sedation remains in your blood
system for about 24 hours you may feel drowsy later on, with intermittent
lapses of memory. If you live alone arrange for someone to stay with you, or
arrange to stay with your family or a friend for at least 12 hours.
If the person collecting you leaves the
department nursing staff will telephone that person when you are ready to go
home. You should be able to go back to work
the day after your colonoscopy unless you are told otherwise. If you experience any of the following
problems please contact your doctor immediately informing them you have had a
colonoscopy:
- Severe abdominal pain (not cramp caused by wind).
- A sudden passing of a large amount of blood from your back passage (a very small amount of blood - take no action).
- A firm and swollen stomach.
- High temperature or feeling feverish.
- Vomiting.
Further Information
Low Fibre Diet
Fibre is the indigestible part of
cereals, fruit and vegetables. Please start a low fibre diet 2 days prior to
your examination.
Foods Allowed on a Low Fibre Diet
Lean tender lamb, beef, pork, chicken,
turkey, offal, bacon, lean ham, fish, Yorkshire pudding, pancakes, bread sauce,
clear and pureed soups, potato (no skins), boiled and mashed, tomato pulp (no
skins or pips), fruit juice (if tolerated), pastry made with white flour, white
bread, white flour, cornflakes, rice krispies, smooth biscuits e.g. Marie,
Osborne, spaghetti and pasta, white rice, crisps, rosehip syrup, ribena, sugar
or glucose in small amounts, boiled sweets, toffees, plain or milk chocolate,
Madeira cake, ice cream, iced lollies, plain or flavoured yoghurt, jelly
marmalade, honey, syrup, tea and coffee (without milk) and fizzy drinks.
Foods to be Avoided on a Low Fibre Diet
Wholemeal, wheatmeal, granary bread,
wholemeal flour, bran biscuits, coconut biscuits, all cereals containing bran
or wholewheat, e.g. shredded wheat, bran flakes, bran buds, muesli, digestive
biscuits, ryvita, ryvita wheat, oat cakes. To enable a more effective examination,
take a clear fluid diet for the period of time stated on the attached
appointment letter.
Fluids Allowed on a Low Fibre Diet
Twenty-four hours before your
examination you should take clear fluids only (no food): Tea (no milk), black coffee, water,
strained fruit juice, strained tomato juice, fruit squash, soda water, tonic
water, lemonade, oxo, Bovril, marmite (mixed into weak drinks with hot water),
clear soups and broths, consommé.
- You may eat clear jellies.
- You may suck clear boiled sweets and clear mints.
- You may add sugar or glucose to your drinks.
Fluids not Allowed on a Low Fibre Diet
Drinks or soups thickened with flour or
other thickening agents.
Source: NHS Choices.
Source: NHS Choices.