What is flexible sigmoidoscopy?

A flexible sigmoidoscopy is a test in which the doctor looks at part of the colon and rectum with a sigmoidoscope – a flexible, lighted tube about the thickness of a finger with a small video camera on the end. It is inserted through the rectum and into the lower part of the colon. Images from the scope are viewed on a display monitor.

Using the sigmoidoscope, your doctor can view the inside of the rectum and part of the colon to detect (and possibly remove) any abnormality. Because the sigmoidoscope is only 60 centimeters (about 2 feet) long, the doctor is able to see the entire rectum but less than half of the colon with this procedure.

Sigmoidoscopy is a diagnosic procedure that allows the physician to examine the lower part of the large intestine -- the rectum and bottom two feet of the colon. It is helpful in identifying the causes of diarrhea, abdominal pain, constipation, abnormal growths and bleeding. A thin, flexible tube is inserted into the large intestine through the rectum. The tube has a tiny light and camera at its end that is connected to a TV monitor, allowing the doctor a good view of this part of the large intestine. If necessary, the doctor may take a small tissue sample (biopsy) from the lining of the intestine to look at later under a microscope.

A sigmoidoscopy typically takes 5-10 minutes, requires only an enema for preparation, and can be done without sedation. Patients may experience some cramping and discomfort during this procedure.

Physicians may also couple a sigmoidoscopy with another procedure known as a double-contrast barium enema. With this, barium is infused into the rectum via an enema tube and an x-ray is taken of the area. The barium helps produce a clearer, more detailed x-ray of the area.