The entire large intestine, or colon, is 5-6 feet in length. Your doctor will only look at the last 1-2 feet of your colon during the flexible sigmoidoscopy.
Now let's discuss your procedure.
To get ready for the procedure, while lying on your left side, you will be asked to bring your knees toward your chest. Once in proper position, your doctor will begin by performing a gentle finger examination of the rectum wearing a clean, lubricated glove. Then, the sigmoidoscope will be placed inside your rectum. You will feel a little pressure when this occurs. The sigmoidoscope is then slowly moved up through the rectum and lower colon.
As this happens, the lining of the intestine is examined carefully on the video screen. Your doctor may use this screen to point out to you, what discoveries are found, if any.
To help move the tube forward, your doctor may send a small quantity of air through the sigmoidoscope to expand your colon. This may cause you to briefly experience a feeling of pressure or cramping in the abdomen.
Depending on what is found during the procedure, your doctor may perform several painless procedures through the endoscope. For example, if your doctor sees an area that looks suspicious, a biopsy, or small sample of tissue, may be taken. When the procedure is finished, your doctor will slowly take out the sigmoidoscope and you can rest comfortably on your back.
The procedure usually lasts for five to fifteen minutes.