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Flexible sigmoidoscopy

Published by Bupa's health information team, June 2009.

This factsheet is for people who are having a flexible sigmoidoscopy or who would like information about it.

A flexible sigmoidoscopy is a procedure used to look inside the rectum and lower part of the bowel.

Your care will be adapted to meet your individual needs and may differ from what is described here. So, it's important that you follow your doctor's advice.

About flexible sigmoidoscopy
What are the alternatives to flexible sigmoidoscopy
Preparing for a flexible sigmoidoscopy
About the procedure
What to expect afterwards
What are the risks?
Questions and answers
Related topics
Further information
Sources

About flexible sigmoidoscopy

A flexible sigmoidoscopy allows your doctor to look inside your rectum (back passage) and lower part of your bowel using a narrow, flexible, tube-like telescopic camera called a sigmoidoscope.

The procedure is used to find out what is causing symptoms such as changes in your bowel habit, and bleeding or pain from your back passage. It's also used to check for colitis, early signs of cancer and polyps.

Flexible sigmoidoscopy is routinely done in the out-patient department and you don't usually need an anaesthetic or sedation.

During the procedure, your doctor may take one or more biopsies (samples of tissue) for examination in a laboratory. If necessary, it's possible to remove polyps and treat haemorrhoids during the procedure.

What are the alternatives to flexible sigmoidoscopy?

Depending on your symptoms and circumstances, it may be possible to diagnose your bowel condition using a different test. The alternatives are listed below.

Barium enema - this involves placing a fluid containing barium (a substance which shows up on X-rays) into your bowel via your rectum. X-ray images of your abdomen (tummy) can then show the inside of your bowel more clearly.
Virtual colonoscopy - this involves having a CT scan of your abdomen. The CT scan uses X-rays to produce three-dimensional images of your lower bowel (colon) and rectum.
Faecal occult blood (FOB) test- this looks for hidden blood in your faeces. A positive result in this test may not mean you definitely have a bowel condition, because other conditions such as gum disease, can also cause blood in faeces. You may still need a sigmoidoscopy.
Colonoscopy - this is like a sigmoidoscopy but looks at the whole of your bowel.

Preparing for a sigmoidoscopy

If you normally take iron tablets, codeine phosphate or medicines that bulk out your faeces, such as ispaghula husk, you will probably be asked to stop taking them for up to two weeks before the procedure. If you normally take other medicines, such as tablets for high blood pressure or diabetes, continue to take these as usual unless your doctor specifically tells you not to. If you're unsure about any medicine you're taking, ask your doctor.

For your doctor to be able to see your bowel clearly, your bowel needs to be completely empty. To help empty your bowel you may be given a strong laxative to take, or you may be given an enema (a fluid which you inject into your back passage) to use before you come into hospital. You will be given instructions on how and when to do this. You can eat and drink normally until you have the enema and after that you should drink clear fluids only. If you have difficulty giving yourself an enema at home it can be given just before the procedure.

You will be asked to sign a consent form. This confirms that you understand the risks, benefits and possible alternatives to the procedure, and have given your permission for it to go ahead.

You will probably be in hospital for between one and two hours.

About the procedure

A sigmoidoscopy usually takes between 10 and 15 minutes. It may feel uncomfortable, but shouldn't be painful. Occasionally, you may be given a sedative before the procedure. This relieves anxiety and helps you to relax. It is given as an injection into a vein in your hand or arm. However, usually you won't need a sedative for this procedure.

You may be asked to put on a gown that opens at the back. While you're resting on your side, your doctor will gently examine your back passage with a gloved finger and then carefully insert the sigmoidoscope into your rectum. Lubricating jelly will be used to make this as easy as possible.

Air is then usually pumped through the sigmoidoscope into your lower bowel to make it expand and to make the bowel wall easier to see. This can cause stomach cramps. It is normal if you get an urge to go to the toilet or pass wind.

A camera lens at the end of the sigmoidoscope sends pictures from the inside of your bowel to a monitor. Your doctor will look at these images. If necessary, your doctor will take a biopsy and/or remove any polyps you have. This is done using special instruments passed inside the sigmoidoscope and shouldn't cause you any pain.

What to expect afterwards

If you haven't had a sedative you will be able to go home when you feel ready. If you have had a sedative you may need to stay a little longer and you will have your blood pressure and pulse taken to monitor your recovery.

Before you leave, your doctor or nurse may explain what was seen inside your bowel during the procedure. If you have had a biopsy or polyps removed, the results will be ready several days later and will usually be sent in a report to the doctor who requested your test.

If you haven't had a sedative you may drive home if you wish. If you have had a sedative someone will need to come and collect you. Sedation temporarily affects your coordination and reasoning skills, so you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours afterwards. If you're in doubt about driving please contact your motor insurer so that you're aware of their recommendations, and always follow your doctor's advice.

Once home, it's sensible to take it easy for the rest of the day. Most people feel able to resume normal activities on the following day.

What are the risks?

Flexible sigmoidoscopy is commonly performed and generally safe. However, in order to make an informed decision and give your consent, you need to be aware of the possible side-effects and the risk of complications of this procedure.

Side-effects

These are the unwanted but mostly temporary effects you may get after having the procedure. After the procedure you may have some mild pain and discomfort. You may also have a swollen abdomen. This usually gets better after a few hours and can ease when you pass wind.

If you have had a biopsy or had polyps removed you may have a small amount of bleeding. This usually stops on its own.

Complications

This is when problems occur during or after the procedure. Most people aren't affected. Complications specific to sigmoidoscopy are uncommon. Possible complications are listed below. The exact risks will differ for every person, so we haven't included statistics here. Ask your doctor to explain how these risks apply to you.

A tear in your bowel - this can happen during the procedure, but it's rare. This can lead to an infection. If you develop a high temperature, severe pain or a swollen abdomen, contact your hospital or your GP as it could mean you have an infection.
Bleeding - this is most likely if you have had polyps removed or a biopsy taken. If you have any heavy bleeding or see blood in your faeces, contact your hospital or your GP.
Side effects from sedatives - sedatives can occasionally cause problems with your breathing, blood pressure and heart rate. These are usually short lived and quickly treated.

No matter how experienced your doctor is at performing the procedure, it's possible that your procedure might not be completed successfully and may need to be done again.