Flexible sigmoidoscopy (flexi-sig) is a short colonoscopy – a way of looking at the inside of the rectum and lower colon through your bottom with a thin bendy tube. It is a quick, very safe examination that can reach 60-70cms into your colon in most cases.
It takes about 3-5 minutes to do the test and, although it can be a bit uncomfortable for some patients, it is more acceptable to most than the older steel rigid instrument called a rigid sigmoidoscope, which only looks inside your rectum and perhaps the lower part of your sigmoid colon. The flexi-sig examines higher up the bowel than the older types of rigid instruments because it can cope with the bends in the bowel. It is very effective and can be done without any sedation in Out Patients with minimal cleansing of the bowel. This is usually done at home using an enema sent through the post with your hospital appointment.
Older patients may need help from a relative or a district nurse, which can be arranged by their GP.
In fact the hospital clinician will be able to do the examination very successfully even without preparation in most patients. So if you can’t manage the enema, it is perfectly OK to keep your appointment without any bowel cleansing.
A colonoscopy is similar to a flexi sig but examines the lining of the whole colon to the appendix or caecum. Full cleansing of the bowel is required, which means taking a preparation the day before, which can be unpleasant. No solid food is allowed until after the test. Your hospital will give you full details of what is involved.
Just before the test, a sedative is usually given and then a thin, flexible tube is passed into the back passage and guided around the bowel.
If polyps are found, most can be removed painlessly, using a wire loop passed down the colonoscope tube. These tissue samples are then checked for any abnormal cells that might be cancerous. Because sedation is given, you will probably need to be collected and taken home. For much older patients, sometimes it is important to have someone with them for the first night after the examination. There is now an alternative to colonoscopy, which doesn’t need sedation although you will still need bowel cleansing. This is called CT colonography or virtual colonoscopy and is a form of X-ray which uses computers to build up an image of your bowel and all your other abdominal organs. If you are keen to avoid colonoscopy ask our doctor about this. It’s down side is that if the CT shows you have a polyp you may still need a colonoscopy as well!
An X-ray examination with laxatives taken the day before to clear out the bowel. On the day, the colon is filled with a thick white liquid (barium sulphate) and X-rays taken from several angles. Expensive and less frequently used to diagnose bowel cancer these days
Virtual Colonoscopy or CT colonography
It is a bit like a computer game of your insides, using scanners and computers to look inside the bowel for polyps and other problems. The scanner uses X-rays to produce two-dimensional and three-dimensional images of the colon and rectum.