What is a Sigmoidoscopy?
A Sigmoidoscopy is a test, which allows the Endoscopist to look
directly at the left side of your 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 Sigmoidoscope has a small camera
attached which is connected to a monitor system where images can
be seen. In order for this test to be successful it is important that we
give you an enema on arrival. This will assist in cleaning your bowel
and enable us to make a correct diagnosis.
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 Sigmoidoscopy 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 of the procedure are discomfort,
bloating and pain. Entonox® (gas and air) may cause nausea,
dizziness and euphoria (heightened self-confidence and happiness).
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 clinician has
advised that this is the most appropriate test for you. If you would like
to discuss alternatives further please speak to your referring clinician.
Your appointment
If you are unable to make your appointment or need to change your
appointment time, please do telephone via the numbers on the back
of this leaflet.
Your appointment time takes into account the time required to admit
you onto the unit. You should therefore not expect to immediately go
through for the test when called. You will be assigned to a Morning
or Afternoon Endoscopy session and will be in the department for
up to 4 hours. Please note we usually have 6 different lists running
consecutively, which may mean some people will have to wait longer
than others, even with the same appointment time.
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.
Please bring a list of all your medications on the day.
Please leave valuables and jewellery at home where possible as we unfortunately are unable to look after these.
What to expect on the day
Before the procedure a nurse will take you into a room and explain
the test and ask you some health questions.
You will be asked to sign a consent form and change your
underwear to some procedural dignity shorts that we supply.
A cannula may be inserted in preparation for your procedure (a small
plastic tube).
We will transfer you to the waiting area and from here you will be
called into the procedure room for your test.
Sigmoidoscopy 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 your job involves any of the above you will need to take the day off
work following the sedation.
After your procedure you will be transferred to our recovery area for
approximately 30 minutes where you will be given a drink and some
biscuits. The nurse will prepare your results and discharge advice.
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.
You will need a responsible adult to accompany you from
the unit because of the effects of the sedation and also have
someone at home overnight after having sedation.
Details of your results and discharge advice will be given before
leaving the unit. Biopsy results will be communicated by the referring
clinician at a later date.
Sigmoidoscopy with Entonox®
If you are having Entonox® (gas and air) instructions will be given on
how to self administer this before your Sigmoidoscopy starts.
Entonox® is inhaled through a mouthpiece to relieve pain.
A cannula (small plastic tube) may be inserted just in case any
medication is needed during your Sigmoidoscopy.
After the procedure you will be transferred to our recovery area for
about 30 minutes where you will be given a drink and some biscuits.
Recovery from the effects of Entonox® is rapid and you will be able
to drive 30 minutes after stopping Entonox®, providing you have had
a straightforward Sigmoidoscopy.
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.
Details of your results and discharge advice will be given before
leaving the unit. Biopsy results will be communicated by the referring
clinician at a later date.
Enema Information
In order to examine the left side of the bowel it must be clear of
all waste materials. This is achieved by using a combination of
changing what you eat and the administration of an enema on arrival
at the endoscopy unit.
7 days before your Sigmoidoscopy appointment please stop taking
iron tablets. Please also stop taking any laxatives that will cause bulk
in your bowels (such as Fybogel®).
4 days before your Sigmoidoscopy appointment please stop
taking medication that might constipate you for example Codeine,
Co-phenotrope (Lomotil®), Loperamide (Imodium®) or Kaolin and
Morphine mixture, Cholestyramine or Colesevelam.
We ask you to have an enema before you have a flexible
Sigmoidoscopy. The enema helps clear your bowel, so the
endoscopist can see all of your bowel clearly. The enema is a small
bottle of fluid that the nurse will administer into your bottom, using a
small tube.
After you have completed the consent documentation, the nurse
will ask you to remove your lower garments and provide you with a
pair of dignity shorts to wear. The nurse will then ask you to lie on a
trolley on your left side, with your knees up towards your chest.
We will cover you with a sheet to maintain your dignity. When you
are ready we will lubricate the small enema tube and insert the tube
and fluid into your bottom. We will ask you to hold the fluid in your
bottom for a short period of time. You will soon get the sensation to
go to the toilet to empty your bowel. You will then be ready for your
test.
Taking Other Medication
Take any medication you are on up to 2 hours before your
appointment with water. If you are taking medication for
DIABETES please read the ‘extra’ leaflet sent alongside this
leaflet.
This leaflet is specific to controlling your diabetes through the various
procedures available within our unit and you will have been sent the
following leaflet:
• Guidance for Managing Diabetes for Sigmoidoscopy or
Colonoscopy
This will give you clear instructions on what to do with your
medication (including insulin) during the preparation for your test.
If you have not received a copy of this leaflet, please contact us via
the phone numbers on the back of this leaflet to request a copy.
Important:
No alcohol should be consumed on the day before and the day of
the procedure.
You may continue to drink water up to 2 hours before your
procedure.
Pre Sigmoidoscopy Diet
Three days before your test please follow a low residue diet, which
consists of the following:
Fats (use sparingly) – Butter or margarine.
Rice – Plain boiled white rice.
Eggs – Boiled or poached.
Meat/Fish – Chicken (skinless) or whitefish.
Cheese – Cream, cottage cheese, tofu or cheese sauce.
Bread – White bread or toast.
Cereals – Crisped rice cereal, cornflakes (no bran).
Pasta – Plain macaroni, spaghetti, noodles.
Potatoes – Boiled, creamed, mashed or baked (no skins).
Dessert – Clear jelly (not red jelly) natural plain yogurt, ice cream
or custard.
Foods to avoid: Red meat, sausage, pies, any fruit or salads,
most vegetables, potato skins, chips, wholemeal or brown bread,
nuts, pulses, baked beans, wholemeal pasta, brown rice, puddings
containing fruit and nuts, cakes, biscuits and yoghurts.
Frequently asked questions
How long does the procedure take?
A sigmoidoscopy usually lasts between 15 and 20 minutes. However,
you may be on the unit for up to 4 hours.
Does it hurt?
Sometimes patients find the test painful, gas and air (Entonox®) or
sedation is available to use for pain relief if needed.
Do I have to have the investigation?
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?
Yes. Mostly you can, however please see page 6 for some
medication specific advice.
Will I be put to sleep for this procedure?
No. Gas and air (Entonox®) or sedation is available (if your
circumstances permit), but you will be awake throughout the procedure.
What shall I wear to attend the procedure?
Please wear loose comfortable clothing. You will be asked to wear dignity shorts for your enema before the procedure. On entering the
procedure room you will be asked to remove your lower clothing
(keeping your dignity shorts and your top clothes on).
Procedure Outcome
Details of your results and discharge advice will be given before
leaving the unit. Biopsy results will be communicated by the referring
clinician at a later date.
If you have any issues or need advice after your procedure
please contact the Gastroenterology & Endoscopy Unit within
working hours (7.45am to 6pm) and ask to speak to the nurse in
charge. See contact phone numbers on the back of this leaflet.
If urgent out of hours advice is required please contact Ward 2
on 01253 953402.
Gastroenterology & Endoscopy Unit Location Map
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 Department
Approved by Medicine Management and Safety Review Committee
Date of Publication 12/06/2025
Leaflet PL/1632(v1)
Review Date 01/06/2028
