What is flexible sigmoidoscopy?

Flexible sigmoidoscopy is a procedure used to investigate problems with your lower bowel or rectum, including pain, bleeding or inflammation. A sigmoidoscopy can also be used to diagnose bowel cancer, or to remove non-cancerous growths, called polyps, from your bowel.

Recent research in the UK has found that people who have a routine flexible sigmoidoscopy between the ages of 55 and 64 will reduce their chances of being diagnosed with advanced colorectal cancer by around one third. At The London Clinic, our specialised team of consultant gastroenterologists perform flexible sigmoidoscopy to detect these and other disorders.

What is a sigmoidoscopy?

Flexible sigmoidoscopy allows your consultant to see inside your sigmoid colon, the lower third of your colon that joins to your rectum. The procedure is done using a sigmoidoscope; a thin, flexible tube containing a miniature video camera and a light at one end. The images from the inside of the bowel are shown on a computer screen in real-time.

How is a flexible sigmoidoscopy performed?

A flexible sigmoidoscopy is a relatively short procedure and only takes about 10 minutes. It is usually done while you’re awake, but you can be sedated if you wish. The procedure shouldn’t be painful, but it may feel slightly uncomfortable.

An enema is given by a nurse to empty the lower bowel, which is essential to allow the doctor to see properly. Your consultant will insert the sigmoidoscope into your anus and guide it through your rectum and sigmoid colon. Once it is in place, the endoscopist inflates your colon with gas in order to provide clearer images that are shown on a screen.

If you have polyps in your bowel, your doctor will usually be able to remove them during the procedure using special tools that are passed through the scope. Tissue samples, called biopsies, can be taken for further analysis in a laboratory.

How should I prepare for a flexible sigmoidoscopy?

Half an hour before the procedure, you’ll be given a very effective enema that will remove solids from the lower part of the colon.
For the couple of days before the procedure, you shouldn’t drink liquids containing red or purple dye, such as beetroot or red wine, as these can look like blood. Instead, stick to natural liquids such as water, fruit juice, coffee or tea.

You should tell your doctor if you have any pre-existing medical conditions or whether you’re taking any special medication or supplements. These include aspirin or other blood thinners, arthritis medication, diabetes medicine, iron supplements or vitamins that contain iron. If you’re taking any of these, please let us know as you may need to stop taking them before the examination.

Recovering from a sigmoidoscopy

Because a sigmoidoscopy is a relatively minor procedure, you’ll usually only need to stay in hospital for a short time afterwards. During this time you may have mild cramping in your lower abdomen until any gas has passed. Unless you have sedation, you’ll usually be able to resume normal activities the same day.