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Flexible sigmoidoscopy

This is a technique to look directly at the lining of the left side of your large bowel/intestine (colon) to try to find out what is causing your problems.

The sigmoidoscope is a thin, flexible tube with a bright light on the end. This tube is passed through the back passage and into your bowel.

It allows samples of tissue (a biopsy) or removal of small warty growths (polyps) to be removed painlessly for testing later.

What are the risks associated with this procedure?

  • Bloating and abdominal discomfort are not unusual for a few hours
  • Perforation of the bowel (a hole in the bowel) is a very rare complication
  • The risk is increased if a polyp needs to be removed (one in 300 cases). This may require an operation to repair the damage
  • Bleeding can be a complication of polyp removal (severe bleeding occurs in less than one in 300 cases). Rarely, this may require a blood transfusion and less commonly surgery.
  • Using sedation can cause breathing complications in up to one in 200 procedures, which usually are not serious.
  • No test is 100% accurate and abnormalities may be missed, including cancers.

A video recording and/or photographs may be taken for your records.

The person doing the test will discuss any questions you may have about the risks.

What are the benefits of this procedure?

Your doctor has referred you for a flexible sigmoidoscopy in order to investigate some symptoms you have been having, such as a change in bowel habit, rectal bleeding, or to review a problem they may have found before, like polyps or colitis. This will benefit you by providing a clear diagnosis.

During the procedure the doctor will also be able to remove small polyps. Like all tests, this is not guaranteed to demonstrate all abnormalities and on rare occasions conditions are not identified.

What are the alternatives to this procedure?

A flexible sigmoidoscopy allows direct inspection of the left side of your large bowel. It is recommended for you because either a full bowel examination is not required or sometimes it is done in combination with another bowel examination to look at the whole bowel. This includes; barium enema, Computer Tomography (CT) scan and a newer technique called virtual colonoscopy.

Preparation

Do not eat for six hours before your appointment. You may have water up to two hours prior to your appointment and may continue with all other medication. Please bring any medication you are currently taking (including sprays and inhalers) with you to your appointment. If you take a number of tablets please bring in your repeat prescription sheet. Please also bring with you a bag to keep your personal items in for whilst you are here.

For patients attending for a diagnostic procedure (to find out what is causing their symptoms) you will be asked to use an enema either at home or at the hospital, to clear out your bowels approximately one hour prior to your procedure time. For patients who require treatment during their procedure, they will be seen by a pre assessment nurse prior to the date of their procedure. At that appointment the pre assessment nurse takes information from you and advises you how to prepare your bowel using a laxative that you drink on the day before your procedure. He/she will also discuss your consent and answer any questions you may have.

For those patients who do not require a pre assessment appointment your consent form will be sent out in the post to you. Please bring it back with you on the day of your procedure. If you are either a diabetic, on warfarin, clopidogrel, rivaroxaban, apixaban, or dabigatran please contact the unit for further information.

If you suffer with Sleep Apnoea and usually use a CPAP machine at night, please bring this with you on the day of your procedure.

Please stop all iron tablets at least four days before your appointment.

If you take medication for your blood pressure, please make sure you take this as usual prior to your procedure with small sips of water (at least two hours before)

Please bring any medication you are currently taking (including sprays and inhalers) with you to your appointment. If you are taking a number of tablets please bring in your repeat prescription sheet.

Please read the information enclosed carefully. If you have any queries contact the unit where you will be having your procedure.

When you arrive at the Hospital

Please report to the reception desk where a receptionist will check your details and direct you to the waiting area. Please be aware the appointment time you have been given, will be your admission time. Your procedure will be carried out as near to this time as possible however on occasions due to emergency patients being seen, this may be delayed.

  • Please do not bring any valuables to the hospital
  • Please bring a dressing gown and slippers for your comfort.
  • Please do not wear any nail varnish, lipstick or jewellery
  • Please bring a contact number of a relative or friend with you

A nurse will then explain the procedure to you, to make sure you understand the benefits, and possible risks as detailed in this leaflet. The staff will want you to be as relaxed as possible for the test and will not mind answering your questions. Provided you are happy for the procedure to be performed, you will be asked to confirm your consent. You will be offered a copy of this.

You will be taken to a room and asked to change into a hospital gown, your slippers and dressing gown. If you have not already taken a bowel cleansing agent at home, an enema will be given to ensure your bowel is completely clean. Just before the procedure you will also see the person doing the test who will be performing the test and they will ask you to confirm your agreement and they will also sign your consent form.

If you need the help of an interpreter to understand any of this information, or on the day of the procedure, please contact the unit where you will be having the test, as soon as possible.

Please note relatives/friends or children should not be used as interpreters when you are required to sign your consent form. You should contact the Endoscopy Unit who will arrange for an interpreter to be present.

During the Test

In the examination room you will be made comfortable on the couch, resting on your left side.

A nurse will stay with you throughout the procedure. The back passage will be examined using a finger before the sigmoidoscope is inserted. When the tube is inserted, air is passed into the bowel to inflate it (distend), which helps to give a clearer view. This may give you wind pains which should not last too long. You may feel the sensation of wanting to go to the toilet, but as the bowel is empty this is unlikely. You may pass wind and although this can be embarrassing for you, just remember staff will understand what is causing the wind. Some discomfort can be caused by stretching of the bowel but this will be kept to a minimum.

The procedure may take five to 15 minutes or more if a polyp has to be removed. If a polyp or biopsy needs to be taken, a wire snare or forceps do this. This is not painful. The base of the polyp is usually cauterised (burnt) in the process. This reduces the risk of bleeding. A sample

of the bowel wall may be taken to help with your diagnosis.

After the test

You will be able to go home soon after the test if you do not have any sedation. If you have sedation you will be asked to stay in the unit to rest for one to two hours as each person can react differently to sedation. You may also have to stay in the unit for about two hours if a polyp has been removed.

Going Home

The wind pains and bloating should have settled. It is important you tell the nurse if they have not, or if they are becoming worse.

If you have had sedation it is essential that a responsible adult comes to pick you up from the unit and accompanies you home by car or taxi. Public transport is not suitable and it is advisable you have the following day off work. Please note the unit closes at 18:00. Your relative/friend should arrive no later than 17:30 to collect you.

When you arrive home it is important to rest quietly for the remainder of the day with someone to look after you for 24 hours.

For the first 24 hours following sedation do not:

  • Drive a car
  • Drink alcohol
  • Take sleeping tablets
  • Operate any machinery or electrical items – even a kettle
  • Sign any legally binding documents
  • Work at heights (including climbing ladders or onto chairs)

Sedation can impair your reflexes and judgement. The effects of the sedation will have worn off by the next day and most patients will be able to resume normal activities but you are advised to have the next day off.

If you have been given Entonox on its own for pain relief, it is important that you feel capable before considering whether to drive. You must wait at least 30 minutes after use before driving or using any machines.

When will I know the results?

The nurse who has been looking after you will be able to give you a brief outline of the test results before discharge from the unit.

If a biopsy or polyp has been removed, the laboratory results will take longer, about four to six weeks. The nurse will advise you to discuss the details of the results and any necessary treatment with your GP or hospital specialist, whoever referred you for the test. You will be given a Patient Centred Report with the outcome of your test written on it.

You will be given written instructions on your procedure and your aftercare and a copy of your report. If you have any questions about the test, please contact the unit where you will be having the flexible sigmoidoscopy.

Last reviewed: 22 April 2024