Flexible Sigmoidoscopy Information

The aim of this leaflet is to help you make a choice about having a flexible sigmoidoscopy. It describes how a flexible sigmoidoscopy is carried out and explains the benefits and risks. It will also help you prepare for the procedure.

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Procedure Information

Please read this leaflet as soon as possible and well in advance of your appointment. If you do not follow the advice on how to prepare for your procedure it may not be possible to do it and you may have to return on another day.

Please bring this booklet and consent form with you when you attend for your appointment.

Helpline or enquiries   (8.30am to 5.00pm Monday to Friday)

For appointments and general enquiries

Boston           01205 445072

Grantham      01476 464366/01205 445072

Lincoln           01522 573849

Louth              01522 573849/01507 631415/631437

For procedure related enquiries (The Endoscopy Units are open 8.30am to 6.00pm Monday to Friday)

Boston           01205 446559

Grantham      01476 464085

Lincoln           01522 573016/01522 512512 ext 458669

Louth              01507 631236

For more information please see:   www.ulh.nhs.uk/services/endoscopy

BOWEL CANCER SCREENING PROGRAMME PATIENTS: Please ring 01522 597548 for all enquiries

Aim of the leaflet

The aim of this leaflet is to help you make a choice about having a flexible sigmoidoscopy. It describes how a flexible sigmoidoscopy is carried out and explains the benefits and risks. It will also help you prepare for the procedure.


You have been advised to have an investigation known as a flexible sigmoidoscopy.

If you are unable to keep your appointment, please notify the department as soon as possible as your appointment may be used for someone else. The booking team will arrange another date and time for you. Please bring this booklet with you when you attend.

Enclosed with this leaflet is a consent form. Your signature is needed for the test to go ahead.

The consent form is an important document. Please read it carefully together with the information in this booklet. Please bring both the consent form and booklet with you to your appointment.

We may contact you a few days before your appointment to discuss the procedure and preparation in more detail. You will be given opportunity to ask questions in the department when you attend for your appointment.

In case of any problems please contact the relevant endoscopy unit (telephone numbers are given on page 2 of this booklet).

What is a flexible sigmoidoscopy?

The test involves looking at the lower part of your large bowel (colon) with a narrow flexible tube called a sigmoidoscope (scope). The scope is inserted through the back passage (bottom) and passed around the bowel. The procedure is performed by, or under the supervision of, a trained doctor or nurse (endoscopist). A light and camera at the end of the scope relay pictures onto a television screen. Carbon dioxide is used to inflate the bowel and help the endoscopist see better.

Samples of tissue (biopsies) may be taken during the test. This is done through the scope. It does not cause any pain and the samples are kept to be looked at under a microscope in the laboratory. Photographs may also be taken for your medical records and may be used for teaching purposes.

The procedure generally takes 10 to 20 minutes.

What are the benefits of having a flexible sigmoidoscopy?

If you have been troubled by symptoms the cause may be found and help decide if you need treatment or further tests.

If a polyp is found this can often be removed during the procedure (there is more information about polyps later in this leaflet).

Flexible sigmoidoscopy may be done as a follow up check if you have had a polyp in the past or other disease of the large bowel.

If a scan or x-ray has suggested there may be something wrong in the large bowel, a flexible sigmoidoscopy allows a closer look at the area.

What are the risks of the procedure?

Complications are rare and may include the following:

Perforation or tear of the bowel (about 1 for every 1,700 cases). About half of those with a perforation will need surgery to repair it.

Bleeding may happen where a biopsy is taken or a polyp removed (about 1 for every 150 cases). This can happen up to 2 weeks after the procedure. It usually stops on its own but may need cauterisation or injection treatment. In some cases a blood transfusion may be needed (around 1 person in every 2,400).

There is a small chance that a polyp or cancer may not be seen (about 5 in every 100 cases). This might be because the bowel was not completely empty or, on rare occasions, that the endoscopist missed seeing it.

In extremely rare cases the procedure can lead to death. However, in a national audit of 20,085 colonoscopies carried out in 2011, no deaths were recorded.

What are the alternatives?

CT colonography (virtual colonoscopy) is an alternative investigation to flexible sigmoidoscopy. This is carried out in the x-ray department and involves some radiation exposure.

If this test shows there could be something wrong in the bowel a flexible sigmoidoscopy may still be needed to look at the area.

Preparing for the investigation

The lower part of your bowel can be cleared using an enema. This will have been sent in the post or given to you. You should administer this at home two hours before your appointment.

Instructions for using the enema are given later in this leaflet.

You may eat and drink normally up until the time you have the enema.  After that you may have only clear fluids until after the examination.

If you feel you will not be able to administer the enema at home, please contact the endoscopy department before your appointment so that we can arrange for it to be given by the nursing staff. There are limited facilities on the unit and if several patients require an enema that day, it may lengthen the time you are in the department or we may have to rearrange your appointment for another date or time.

Sometimes it is necessary to drink a laxative medication (also called ‘bowel preparation’) to clear and empty your bowel. If you have been supplied with a packet of laxative then please follow the instructions in the ‘How to take your bowel preparation’ booklet. If you do not have this booklet please contact any of the booking teams (numbers on page 2 of this booklet) or access online at www.ulh.nhs.uk/services/endoscopy

What if I take medication?

You should continue your regular medication as normal. However, if you are taking iron tablets you should stop these at least 5 days before the procedure (7 days if possible). If you take Fybogel, Regulan, Proctofibe, Loperamide (Imodium), Lomotil, or codeine, please stop taking these at least 3 days before your appointment.

Blood thinning medication (anticoagulants)

Sometimes these medications need to be stopped and if this is the case the person who referred you for the test should have given you clear instructions. If you are unsure please contact your consultant’s secretary. For your safety, if the correct instructions are not followed, it may not be possible to do the procedure and you may have to return on another day.

Warfarin: unless you have been advised to stop this medication, continue taking it and have your INR checked within the week before the test. The procedure may be cancelled if your INR has not been checked within the last 7 days. It should be within your target range. If you have been advised to stop your Warfarin you should do so for 5 full days before the procedure (take your last dose 6 days before) and have your INR checked the day before the procedure. It needs to be less than 1.5 for the procedure to go ahead. IMPORTANT: please bring your yellow book to the appointment.

Dabigatran, Rivaroxaban, Apixaban or Edoxoban: please do not take on the morning of the procedure. If you have been advised to stop taking this medication you should take your last dose 3 days before the procedure.

Clopidogrel (Plavix), Prasugrel or Ticagrelor: these medications can generally be continued but if you have been advised to stop you should do so for 7 full days before the procedure (take your last dose 8 days before).

What happens when I arrive?

When you arrive in the department please book in at reception. It is our aim for you to be seen as soon as possible after your arrival. However, if the department is very busy your appointment may be delayed. The department looks after emergency patients who will be seen first if needed.

A nurse will take you through to the admission room and ask you about your general health to check if you are fit to have the procedure. You will also be asked about your plans for getting home afterwards.

The nurse will make sure you understand the procedure and discuss any further concerns or questions you may have. If you are happy to go ahead, you will be asked to sign your consent form.

Your blood pressure and heart rate will be checked and you will be asked to remove your lower clothes and put on a hospital gown.

What will happen during the procedure?

The nurse will take you through to the procedure room and you will have the opportunity to ask any final questions. You will be asked to lie on a trolley on your left side with your knees bent and the nurse will place an oxygen monitoring probe on your finger.

The endoscopist will usually examine your back passage with a gloved finger before inserting the scope. The bowel has natural bends which may cause some discomfort but this should not last long. You may also feel bloated due to the gas that is used.

The endoscopist may ask you to change your position during the procedure as this can help with the passage of the scope.

If you feel you need something to ease any discomfort during the procedure, ‘Gas and Air’ (Nitrous Oxide) is available. This is a gas that you inhale through a mouthpiece. If you have Nitrous Oxide you will need to wait for at least 30 minutes before you can return to normal activities such as driving. If you would like more information please ask the admitting nurse.

What happens after the procedure?

After the procedure you will be taken to the recovery area where you will be able to rest if needed. You will then be able to get up and dressed. Before you leave the department the nurse or doctor will explain the findings and if any medication or further tests are required.

You may feel some mild to moderate windy pains in your abdomen (tummy). Although these may be unpleasant they are normal and should stop within a few hours. If you had a polyp removed or a biopsy taken you may see a little bleeding from your back passage.

Most people are able to return to work after the procedure but this may depend on the type of work that you do. Some people feel the need to rest for a few hours afterwards. Most people are able to resume normal activities within 24 hours.

What happens if a polyp is found?

A polyp is an overgrowth of cells on the inner lining of the bowel. Polyps may be raised on a stalk like a mushroom (pedunculated) or flat (sessile). Polyps are generally removed or sampled (biopsied) by the endoscopist as they may grow over time and cause problems in the future. This does not cause any pain.


Polyps with a stalk are usually removed using a wire loop (snare) which is placed around the stalk. Heat is passed through the wire which cuts through and cauterises any blood vessels. Flat polyps are often removed by injecting the tissue around the polyp with fluid to raise the area away from the deeper layers. A hot wire snare is then used to remove the polyp.

Smaller polyps may be removed with a cold wire snare or pinched off the bowel wall with forceps. Polyps are sent to the laboratory to be looked at under a microscope. Your consultant may write to you with the results or give them to you at your next clinic appointment if you have one. You may also contact your GP. Routine results are usually available within 4-6 weeks but can sometimes take a little longer.

What are the risks of removing polyps?

After removal of a polyp there is a risk of bleeding and/or a hole forming in the bowel wall while the area heals. The healing process can take up to 2 weeks. It is advisable not to travel abroad for this period if large polyps are removed. Please tell the nurse or doctor if you have plans for travel after your procedure.

In most cases you can resume normal activity afterwards but if you have had a large polyp removed you may be advised to avoid heavy lifting or strenuous exercise for 2 weeks to reduce the risk of complications.  It is important to attend the accident and emergency department if you pass any fresh blood or clots (more than a few tablespoons) or if you have severe pain or swelling in the abdomen (tummy) which persists and does not get better.

Phosphate enema: directions for use

  • Lie on your left side if possible with both knees bent, arms at rest
  • Remove the protective shield while holding the bottle upright and grasping the grooved bottle cap
  • With steady pressure, gently insert the enema into your bottom with the tip pointing towards the navel (tummy button)
  • Squeeze the bottle until nearly all the liquid is expelled. Stop if there is any resistance or pain. Forcing the enema can result in injury
  • Stay near to a toilet as the urge to empty your bowel can come on quickly
  • Wait until the urge to use the toilet is strong. This is usually between 2 and 5 minutes

What must I remember?

  • If you are not able to keep your appointment please notify the endoscopy department as soon as possible. Telephone numbers are given at the beginning of this leaflet
  • It is our aim for you to be seen as soon as possible after your arrival. However, the department is very busy and your appointment may be delayed. If emergencies occur, these patients will be seen before less urgent cases
  • The hospital cannot accept any responsibility for the loss or damage to personal property during your time in the department

If you have any problems or concerns after administering the enema or you are worried about any symptoms you experience after the flexible sigmoidoscopy, you may ring the enquiry numbers on page 2 of this booklet. Out of hours please contact the NHS non-emergency service on 111.