What is a Colonoscopy?
A Colonoscopy is a test, which allows the Endoscopist to look
directly at the whole of the large bowel (Colon). In order to do this,
a flexible tube the thickness of a finger, is carefully passed through
the anus into the rectum and into the large bowel. This can be
uncomfortable as bends in the colon are negotiated and air is used
to inflate the colon. The Colonoscope has a small camera attached
which is connected to a monitor system where images can be seen.
Benefits
By examining your bowel the cause of your symptoms may be found.
Images and biopsies (samples) may be taken and sometimes polyps
(small growths in the bowel) can be removed or other treatments
performed.
Risks
A Colonoscopy is a safe examination but rarely, a complication such
as bleeding or perforation may occur (1 in 1500, or if polyps removed
1 in 200). Other risks are discomfort, bloating and pain. Entonox®
(gas and air) may cause nausea, dizziness and euphoria. Sedation
may cause nausea and vomiting, and rarely you may become over
sedated which can reduce your breathing rate.
Alternative treatments
There may be alternatives to this procedure and sometimes a
dedicated bowel CT scan is done instead. Your referring clinical
team have advised that this is the most appropriate test for you. If
you would like to discuss alternatives further please speak to the
clinical team on your ward.
What to expect on the day
The Endoscopy unit will coordinate with your ward team with regards
to special instructions prior to the procedure.
The Colonoscopy may be undertaken after you have taken bowel
preparation. In order for the test to be successful, it is important that
you take the bowel preparation as directed by the clinical team on
the ward. This will assist in clearing your bowel, enabling us to make
a correct diagnosis.
Before the procedure an endoscopy nurse will explain the test and
ask you some health questions. They will answer any questions or
concerns you may have.
You will be asked to sign a consent form.
A cannula will have been inserted in preparation for your procedure
(a small plastic tube).
We will transfer you to the Endoscopy Unit. You may have to wait for
some time until the procedure room is available. When it is your turn,
you will be taken into the procedure room for your test.
In the endoscopy room the procedure will start with you lying on your
left side on a trolley. You may be asked to change position during the
procedure.
Please be aware we are a Teaching Hospital and may have trainees
in any areas of your pathway. They will always be supervised and
they will always be working at an appropriate level for their training
stage. If you would rather not have a trainee involved in your care
please let the staff know your wishes. This will not affect your care.
Colonoscopy with Entonox
If you are having Entonox® (gas and air) instructions will be given on
how to self administer this before your Colonoscopy starts.
Entonox® is inhaled through a mouthpiece to relieve pain.
A cannula (small plastic tube) will be inserted just in case any
medication is needed during your Colonoscopy.
After the procedure you will be transferred to our recovery area and
then subsequently back to your ward. The Colonoscopy result will be
communicated to you by the clinical team on the ward.
Recovery from the effects of Entonox® is rapid.
You may feel bloated with wind-like discomfort. This is normal and
usually settles quickly. If you have a biopsy taken or a polyp removed
it is common to pass small spots of blood from your bottom for a day
or two following the procedure.
Colonoscopy with Sedation
You will need a cannula (small plastic tube) in your hand or arm
through which a mild sedation and analgesia (pain relief) is given.
This should relax you but will not put you to sleep. It is not a
general anaesthetic.
You will be awake and aware during the procedure with sedation.
Sedation may cause loss of memory and judgement for 24
hours after the test. You must not:
• Drive
• Drink alcohol
• Operate machinery
• Sign legal documents
If you are discharged from the ward within 24 hours of your
procedure you will need someone to accompany you home and
to remain with you overnight as the effects of the sedation will
still be in your system.
After the procedure you will be transferred to our recovery area and
then subsequently back to your ward. The Colonoscopy result will be
communicated to you by the clinical team on the ward.
You may feel bloated with wind-like discomfort. This is normal and
usually settles quickly. If you have a biopsy taken or a polyp removed
it is common to pass small spots of blood from your bottom for a day
or two following the procedure.
Frequently asked questions
How long does the procedure take?
A Colonoscopy lasts between 30 and 60 minutes.
Does it hurt?
Sometimes patients find the test painful but gas and air (Entonox®) or
sedation is available to use for pain relief if needed.
Do I have to have the test?
No. The choice is yours, please refer to page 3 for alternatives and
the reason why this test is appropriate.
Can I take my tablets as normal?
Please take medications before and after the procedure as
instructed by the clinical team on your ward.
Will I be asleep for this procedure?
No. Gas and air (Entonox®) or sedation is available (if your
circumstances permit), but you will be awake throughout the
procedure.
Procedure Outcome
After the procedure you will be transferred to our recovery area and
then subsequently back to your ward. The Colonoscopy result will
be communicated to you by your clinical team on the ward. Biopsy
results will be communicated by your referring clinician at a later
date.
Colonoscopy Illustration
Access from the main hospital multistorey car park
We are located in Area 6 - Gastroenterology & Endoscopy Unit,
highlighted in orange on the main hospital map. Follow the signs for the
Main Hospital up the escalator/lift towards Area 6, second corridor on the
left. Follow the signs down the link corridor, exit to the right via the side
door (external) which is signposted for Patient Entrance to Reception.
Access for drop off/collection only & disability parking
Enter via East Park Drive and follow the road up the hill, take the
second left signposted for Gastroenterology & Endoscopy Unit Drop
Off Only, follow the road round to the right.
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Author Gastroenterology and Endoscopy Unit
Approved by EUG Meeting
Date of Publication 18/02/2026
Reference No PL/908 (V4)
Review Date 01/02/2029
