Flexible Sigmoidoscopy

Like other forms of endoscopy, flexible sigmoidoscopy gives your doctor a chance to look inside your digestive tract—in this case, the lower portion of your colon, or large intestine. Your doctor may perform a flex sig, as it's also called, to check for signs of colon cancer or the source of bleeding in the lowest part of the colon, called the rectum.

During the procedure, your doctor will insert a flexible tube called an endoscope through your anus and into your rectum and lower colon. The tube carries a light and a tiny camera so your doctor can look carefully at the tissue inside your lower colon and rectum.

The endoscope also allows medical instruments to be inserted into the lower colon so your doctor can take tissue samples, or biopsies. Your doctor can also remove abnormal growths called polyps if you have them. A small amount of air may also be pumped through the tube to make it easier to see inside your digestive tract.

Preparing for your Flexible Sigmoidoscopy

Unlike colonoscopy, you don't have to be sedated for this short procedure. Like a colonoscopy, however, you'll have to prepare for the procedure by clearing your digestive tract. This includes spending a day or two on a diet of clear liquids and possibly taking laxatives or an enema as directed by your gastroenterologist.

Flexible sigmoidoscopy only shows your doctor the lower portion of the colon. Depending on what your doctor finds during the flexible sigmoidoscopy and/or how your symptoms continue or develop, you may need to follow up with a colonoscopy.