Please Upgrade Your Browser.

Unfortunately, Internet Explorer is an outdated browser and we do not currently support it. To have the best browsing experience, please upgrade to Google Chrome.


Flexible Sigmoidoscopy

The Procedure

This is a test to look at the left side of the large bowel or colon. It is done by a colonoscopy specialist.
It should take between 10- 15 minutes, although the whole appointment may take around two hours.
During this test, the specialist uses a thin flexible tube (a colonoscope) with a tiny camera on the end to look inside your bowel. The tube is about the width of your little finger and is passed through the anus (back passage) into the bowel.

Why do I need a flexible sigmoidoscopy?

You have been advised to undergo this investigation of the left side of your large bowel to help find the cause for your symptoms and if necessary, to decide on further investigations and treatment.
The doctor doing the test will normally be able to give you preliminary results on the day.
Preparation for the test
To ensure that we can get a clear view of the bowel, you may be given an enema or a strong laxative, which gives you diarrhoea.

Is the test painful?

Having the test can make you feel uncomfortable, and to help with this, you can have “gas and air” (Entonox) which is a quick acting form of pain relief and is out of your system very quickly.

You will be able to drive home straight after the test if you have this form of pain killer. However, some people need something stronger, and in this situation, you can be given sedation. This can make you feel a little bit sleepy. The sedative is usually given by injection into your arm and may make you drowsy. You may be less alert than usual for up to 24 hours.

So, if you have the sedative, it is important that you:

  • don’t drive home - have someone pick you up from the hospital
  • don’t drink alcohol for 24 hours don’t operate machinery

Are there any risks with a flexible sigmoidoscopy?

A sigmoidoscopy is usually safe but in rare cases it can cause harm to the bowel. In about 1 in every 5000 people it can cause a small tear in the bowel. If you have bleeding that is difficult to stop or a tear in your bowel, you will be admitted to hospital straight away. Some people will need surgery to repair their bowel.

Are there any alternatives to a flexible sigmoidoscopy?

This test is the best test to look at the left side of your bowel. However, please note that occasionally the test may need to be abandoned or may be incomplete. This can happen if you find the procedure too uncomfortable or if the bowel preparation did not empty your bowel completely. In this case, the test may need to be repeated or we may suggest an alternative procedure. The most common subsequent test to request is a CT scan to look specifically at the large bowel. This is called a CT pneumocolon.

Should I take all my normal medication before the test?

You should have had a chance to discuss any medications you are taking with one of our nurses or doctors before your procedure. If you are taking anti- platelet medication or anticoagulant medication to prevent the formation of blood clots (such as aspirin or clopidogrel, warfarin, rivaroxaban or dabigatran); sedatives, chronic pain medication, or medications for diabetes, please let the doctor or nurse know in good time before the date of your procedure. You should continue to take all of your medications as normal, unless you have been told otherwise by the doctor or endoscopy nurse.

Related Advice Articles

No items found.

Bringing healthcare closer to where you live.

One Health Group utilises specialist consultants and healthcare managers working together to provide the best possible diagnosis and treatment for our patients.