Flexible sigmoidoscopy is a procedure that enables me to examine the lining of the rectum and lower bowel or colon. A lubricated soft, flexible tube about the thickness of the index finger is gently inserted into the anus (rectal opening) and moved into the rectum and the lower part of the colon.
Flexible sigmoidoscopy is performed to investigate symptoms such as diarrhoea, bleeding, changes in bowel habits or urgency.
A sigmoidoscopy usually takes between 10 and 15 minutes. It may feel uncomfortable, but shouldn’t be painful. Usually, I will give a sedative before the procedure. This relieves anxiety, helps you to relax and forget what’s going on! It is given as an injection into a vein in your hand or arm.
You will be asked to put on a gown or shorts that open at the back. While you’re resting on your left side, I will gently examine your back passage with a gloved finger and then carefully insert the sigmoidoscope into your rectum. Lubricating jelly will be used to make this as easy as possible.
Air is then usually pumped through the sigmoidoscope into your lower bowel to make it expand and to make the bowel wall easier to see. This can cause stomach cramps. It is normal to get an urge to go to the toilet or pass wind.
A camera lens at the end of the sigmoidoscope sends pictures from the inside of your bowel to a monitor. I will look at these images. If I see an area that needs more detailed evaluation during the procedure, a small sample or biopsy may be obtained and submitted to a laboratory for analysis. This is done by placing a special instrument (forceps) through the sigmoidoscope; this is usually painless. If I find a small growth or polyp, I may attempt to remove it (polypectomy) using a special piece of equipment called a snare; or instead I may request that you have a colonoscopy, which is a complete endoscopic examination of the entire colon and remove it at that time.
Flexible sigmoidoscopy is commonly performed and generally safe. However, in order to make an informed decision and give your consent, you need to be aware of the possible complications of this procedure. Complications are rare, however, they may occur. They include bleeding from the site of a biopsy or polyp removal (less than 1 in 100 cases) or a tear (perforation) of bowel wall (less than 1 in 1000 cases). It is important to contact me (via Spire Hospital switchboard) if you notice symptoms of severe abdominal pain, abdominal distension, nausea, fevers, chill, or rectal bleeding equal to more than half a cup. Bleeding can occur up to several days after removal of a polyp.
No matter how experienced your doctor is at performing the procedure, it’s possible that your procedure might not be completed successfully and it may need to be done again.
If sedation is to be used, then you will be asked to fast for 6-8 hours before the procedure. Most of your medications can be continued as usual but if insulin is required this should be avoided until after the procedure.
The rectum and lower colon must be completely emptied of stool for the procedure to be performed. Usually an enema placed about 30 minutes before the procedure is all that is necessary, but laxatives or dietary modifications may be recommended in certain instances. A nurse will either give you instructions on how to insert the enema or offer to help you with this.
You will be monitored in the recovery area for 15-30 minutes until the effects of the sedatives start to wear off. Normally you will be offered a drink and a light snack once you are fully awake (about 30-45 minutes after the endoscopy). You may have some mild cramping or bloating from the air that was placed into the colon during the examination. This should quickly improve with the passage of flatus.
I will come and see you before discharge to inform you of the results and to answer any questions that you may have. I write, usually 5-7 days later, with the results of any samples taken during the flexible sigmoidoscopy.
Sedatives will affect your judgment and reflexes for the rest of the day. You should not drive, operate machinery, drink alcohol or make legal decisions for 24 hours after having the sedative. You will need somebody to accompany you home and to stay with you until the effects have fully worn off. Most people are able to resume normal activities after 24 hours.