Flexible sigmoidoscopy enables the physician to look at the lower portion (left side) of the colon (rectum, sigmoid, and descending colon). This procedure evaluates bleeding, diarrhea, abnormalities on x-ray studies, inflammatory bowel disease activity, as well as other indications. This examination is intended to view only the lower third of the colon.
A flexible sigmoidoscopy takes 5-10 minutes, in which your physician inserts a flexible, video endoscope (a tube with a camera and light on the end of the scope) into your rectum and advances the instrument with direct visualization into your colon. The scope transmits an image of the inside of the colon onto a video monitor allowing the physician to carefully examine the lining of the last portion of the colon. The physician will use air and water to open up the colon to allow better visualization. Biopsies can be taken by passing forceps through the scope and are not sensed as there are no nerve endings for pain on the inside lining of the colon. You may feel pressure or cramping in your lower abdomen as air is added to the colon and the scope is advanced. Most patients report the discomfort as minor.
Bleeding is possible if biopsies are taken and rarely of significance. The risk of perforation is 1 in 5000 to 10,000 cases. If sedation is used, there is a low, but potential risk of a reaction to the sedation.