Flexible Sigmoidoscopy

A flexible sigmoidoscopy is a nonsurgical outpatient procedure that is used to view the inside lining of the rectum and lower section of the colon (known as the sigmoid colon or descending colon).

A sigmoidoscope is a long, thin tube equipped with a light and a viewing instrument that sends images to a monitor. A gastroenterologist may perform a flexible sigmoidoscopy to look for a number of conditions or diseases in the lower colon or rectum, such as:

• Inflammation
• Polyps 
• Ulcers
• Cancer

A sigmoidoscopy is most frequently used as a screening tool for colon cancer. It is helpful in determining the cause of abdominal pain, unexplained weight loss, bowel obstruction, changes in bowel habits, or bleeding from the anus. The doctor can also obtain a tissue sample (biopsy) and remove any polyps found during the procedure.

How to Prepare for Flexible Sigmoidoscopy

You will need to undergo bowel prep similar to preparing for a colonoscopy. Your doctor will provide you with specific instructions. Your doctor will also let you know if or when you should adjust or stop any medications you take. This procedure does not require sedation or general anesthesia, so you do not need a driver to accompany you.

What to Expect

Flexible sigmoidoscopy does not require any kind of sedation. You will lie on your left side with your knees bent for the procedure, also known as the fetal position. Your doctor may first perform a digital rectal exam to check for obstructions.

Your doctor will then insert the sigmoidoscope through your anus into your rectum and the lower section of your colon. Air is pumped through the sigmoidoscope to inflate the colon so it is easier to see. A small camera mounted on the endoscope transmits live images to a video monitor. You may need to change positions during the procedure so the scope can be adjusted for better viewing.

Special instruments may be inserted through the sigmoidoscope to obtain tissue samples or remove abnormal growths.

A flexible sigmoidoscopy takes about 20 minutes. The procedure may cause temporary discomfort, such as mild cramping or bloating. It is common to pass gas during and after a flexible sigmoidoscopy.

Your doctor will review the results of your flexible sigmoidoscopy with you after your procedure or during a follow-up appointment. It may take time to receive biopsy results. If polyps or other abnormal tissues are found, the doctor may suggest examining the rest of the colon with a colonoscopy.