Flexible Sigmoidoscopy

What is a flexible sigmoidoscopy?

A flexible sigmoidoscopy is an examination of the inside of the lower part of the large bowel, using a slim flexible tube passed through your anus. The tube contains a digital camera, allowing the endoscopist to look for problems which may be causing your symptoms. The procedure takes about 15 -20 minutes.

Do I need an anaesthetic?

A general anesthetic is not required for this procedure.

Patients may choose to have Entonox, gas & air, which is inhaled via a mouthpiece. You can resume your normal activities including driving 30 minutes following your procedure.


After your procedure, you will receive your results, and be free to go home within 30 minutes.

The endoscopy report and results of any samples will be sent directly to your own doctor. You may eat and drink as normal after the examination.

Giving Blood after the Procedure

You will be unable to donate blood for 4 months following your procedure. If you have been informed that you have had any biopsies taken, or any polyps removed.

What are the risks of flexible sigmoidoscopy?

The majority of flexible sigmoidoscopies are very safe and uncomplicated, particularly in community based units like ours. A few people who have the procedure will experience mild abdominal discomfort, such as cramp, soreness in the back passage and loose motions for a few days after the test or slight bleeding from the lower part of the bowel.

Rarely, patients may have a reaction to Entonox, bleeding or perforation (tear in the lining of the bowel wall). These would require admission to hospital for treatment.

Within the Endoscopy Unit, we only remove small polyps to reduce this risk, and refer any large polyps to our colleagues within the hospital. Very rarely an abnormality may not be identified due to poor bowel preparation. This may occur in less than 5% of cases, or where a polyp is smaller than 1 centimetre. Please speak to your endoscopist if you are concerned, or would like more information.

Do I need to bring anything with me?

Make sure you bring a list of any medications you are taking. It is important to bring asthma inhalers, angina sprays and diabetic medication. Bring your consent form. You may sign this at home if you feel you have enough information.

What preparation is required before a flexible sigmoidoscopy?

For this examination to be successful, your bowel must be empty. It is important that you take the bowel preparation sent to you and follow the detailed instructions on how to take it and what you can eat and drink.

Please try to avoid eating seeded foods for one week prior to your procedure.

Anticoagulant advice: If you are taking Clopidogrel, or other antiplatelet tablets, you may be asked to stop it 5 days before the procedure if it is considered safe for you to do so. If this applies to you details will be included in your appointment letter. You do not need to stop taking aspirin If you take warfarin or other blood thinning tablets, please contact us as you may have to stop them prior to the procedure. If you have to stop warfarin it is usually for 5 days before your appointment and you need to have an INR done at your practice the day before and bring the result along with you on the day of the procedure.

If you are taking Apixaban, Rivaroxaban, Dabigatran or Edoxaban, please omit on the day of the procedure.

If you are taking iron tablets please stop 1 week prior to your procedure date.

About the flexible sigmoidoscopy procedure

A nurse will check your details, blood pressure pulse and allergies and explain the procedure. If you haven’t signed your consent form, the nurse or endoscopist will explain and sign it with you. We will ask you to change into a gown for comfort.

In the procedure room you will be made comfortable on a trolley, lying on your left hand side. A device will be attached to you to measure your heart rate and oxygen levels. We will give you some oxygen through a nasal cannula (slim tube just inside your nostril) If you are having sedation, or using Entonox (gas and air) this will be administered before the endoscopist starts the procedure. To help with the endoscope moving easily round the bowel, you may be asked to turn to your back or other side.

A biopsy (small sample of tissue) may be taken during the examination to be sent to the laboratory for more tests. You cannot feel this being done. The examination takes between 30-40 minutes.

A nurse will be with you to monitor and reassure you throughout the examination.