Flexible sigmoidoscopy

This information is for patients who are having an examination of the large bowel known as a flexible sigmoidoscopy.  It explains what is involved, and any significant risks that there may be.

Flexible sigmoidoscopy is an examination which allows visualisation of the lower part of the large intestine or colon using a colonoscope, a flexible tube smaller than the thickness of the little finger. Sometimes a sample of the lining of the bowel (a biopsy) is taken for laboratory examination. If polyps (projections of tissue rather like warts) are found, they can be removed during the examination. The procedure takes on average about 5-10 minutes. Normally you will be able to go home 30-45 minutes later.

Preparation for the examination

• for this examination to be successful and allow a clear view of the colon, your bowel must be as empty as possible and so to enable this you will be given an enema in the endoscopy unit before the examination.

• if you are taking blood thinning medications (e.g. warfarin or other anticoagulants, clopidogrel or other anti-platelet agents) please inform us. You may continue to take other medications as normal, except iron tablets or stool bulking agents (eg. Fybogel, Movicol or Laxido) which should be stopped one week before your examination.

• please bring a list of any medications you are currently taking; it is especially important to remember to bring any asthma inhalers or angina sprays with you.

On arrival to the Endoscopy Unit

• a nurse will check your details, blood pressure and pulse. If you are allergic to anything (medications, plasters, latex), please tell the nurse. Please let us know about any medication you may be taking or if you are allergic to any medications, plasters, latex etc.

• the procedure will be explained again and you will be asked to sign a consent form to confirm that you understand the examination and agree to go ahead with it.

What does the examination involve?

• a small device for recording the pulse and breathing will be attached to your finger and you will be given oxygen.

• you are helped to lie in a comfortable position on your left side and then the colonoscope is be passed into your back passage and around the large bowel. Flexible sigmoidoscopy examines the lower part of the bowel and your doctor has deliberately chosen this rather than a colonoscopy that looks at the entire bowel.

• air will be passed into the bowel to expand it so the bowel lining can be seen more clearly.  This may give you some discomfort, but it will not last long. Some may come out again as wind.  This is quite normal.

• you may feel as if you want to go to the toilet, but as the bowel is empty you do not need to worry about it actually happening. Any remaining fluid in the bowel will be removed by the colonoscope.

• a biopsy may be taken during the examination to be sent to the laboratory for further tests.  Similarly, any polyps may be removed during the examination. You cannot feel biopsies or polyps being removed but you can sometimes visualise what is happening.

Do I need to have sedation for a flexible sigmoidoscopy?

Many patients having this procedure do not require sedation as it is short lasting and usually involves brief discomfort only. If you prefer then sedation can be given. This involves an injection into a vein that causes relaxation and sometimes drowsiness. We have Entonox (gas and air) available and this is suitable for some patients.

After the examination

• you will return to the recovery area to rest for at least 30 minutes. Once recovered you may eat and drink as normal.

• the result of the examination will be available before you go home.  Any biopsy results will take longer.

• even though you feel fully awake after having sedation it is important to arrange for somebody to pick you up from the hospital, or if arranging transport home for somebody to be there to look after you. They can then deal with any problems that may arise, despite this being very unlikely.

• if you have sedation you do not attempt to drive for 24 hours.

Are there any significant risks?

This test is very safe, but very rarely there can be a problem, for example

• a reaction to the sedative. The sedative can affect your breathing making it more slow and shallow.

• when a biopsy is taken or a polyp is removed, there may often be a little bleeding which usually stops by itself. More serious bleeding is very rare.

• perforation, which is a tear in the wall of the colon.  This will require a stay in hospital and treatment with antibiotics, and may require surgical repair. This is extremely rare.

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