During a flexible sigmoidoscopy, a narrow and flexible tube called a sigmoidoscope is passed through your anus to examine your rectum and the lower part of your bowel. This area is often called the sigmoid colon. Your doctor may recommend a flexible sigmoidoscopy if you have had a change in bowel habits such as persistent diarrhoea, bleeding, a family history of bowel cancer, or pain in the lower abdomen. You may also have a flexible sigmoidoscopy if an inflammatory bowel disease such as ulcerative colitis or Crohn’s disease is suspected.
A flexible sigmoidoscopy is a quick procedure and usually only takes between 10 and 20 minutes to complete. It allows your doctor to see inside your sigmoid colon, and also allows samples (biopsies) to be taken if necessary. A flexible sigmoidoscopy provides a more accurate picture than say an X-ray would.
Your flexible sigmoidoscopy will be performed by your doctor or by a nurse specialist. When you arrive, you may be asked to change into a hospital gown that opens at the back.
It is unlikely you will need a sedative for a flexible sigmoidoscopy, but if you do, a cannula will be placed into the back of your hand which is where the sedative is administered. A sedative will make you feel a little drowsy and will also help you feel more relaxed during the procedure. You may also receive a painkiller to help you feel more comfortable too.
You will be asked to lie on your left side and your doctor will gently examine your back passage with a gloved finger before carefully inserting the sigmoidoscope. Lubricating jelly will be used to make this as easy as possible. Your doctor will slightly inflate your bowel with air in order to see the inside lining easier. A camera lens at the end of the sigmoidoscope sends pictures from the inside of your bowel to a monitor in the procedure room. If necessary, biopsies may be taken and polyps removed if you have any.
A flexible sigmoidoscopy is usually performed as a day case procedure, which means there is no need for an overnight stay in hospital. Your doctor will tell you whether you need to stop taking any medications beforehand such as warfarin or ibuprofen, as these may cause complications during the procedure.
Your bowel will need to be completely empty for a flexible sigmoidoscopy so that your doctor can clearly see the lining of your sigmoid colon. In order to do this, you will be required to have an enema beforehand to clear the lower part of your bowel. It is also recommended that you eat a light meal the day before and drink plenty of clear fluids to easily clear the bowel.
You will also be told to stop taking iron tablets if you do so, as these make the inside of your bowel black which makes it harder for your doctor to clearly see inside the bowel.
If you are having sedation for your flexible sigmoidoscopy, you must ensure someone is able to collect you after your procedure as you will not be able to drive or work for a minimum of 24 hours.
You will be given full instructions for preparation beforehand by your doctor or nurse. It is important at this stage to discuss any concerns or answer any questions you may have.
If you had no sedative for your procedure, you should be able to go home as soon as you feel ready to. If you have had sedative, you should be able to leave within an hour after your procedure, or once the effects of the sedative have worn off. You will not be able to drive for 24 hours, and it is important someone remains with you during this period. Even if you feel that the sedative has worn off shortly after, it can stay in your blood and you may experience further drowsiness.
If you feel that you need pain relief, over the counter medicines such as paracetamol or ibuprofen can be taken.
A flexible sigmoidoscopy is a safe and routine procedure, with most people having no complications or side effects. You may feel bloated after your procedure due to the air which is used to inflate the bowel, and you may also have slight bleeding if you had a biopsy taken or a polyp removed.
The most significant complication of a flexible sigmoidoscopy is perforation or a tear of the lining of the bowel and heavy bleeding after the removal of a polyp or biopsy. The risk however is low.