Sigmoidoscopy is a procedure used to see inside the sigmoid colon and rectum.
You will be asked to lie on your left side with your knees drawn up to your chest.
A gastroenterologist or surgeon usually performs the test.
The doctor will carefully place a gloved and lubricated finger into your rectum to check for blockage and gently enlarge (dilate) the anus. This is called a digital rectal exam.
Next, a flexible tube with a camera on the (sigmoidoscope) is placed through the anus. The scope is gently moved into your colon. Air is inserted into the colon to enlarge the area and help the doctor see better. The air may cause the urge to have a bowel movement or pass gas. Suction may be used to remove fluid or stool.
The doctor may take tissue samples with a tiny biopsy tool inserted through the scope. Heat (electrocautery) may be used to remove polyps. Images of the inside of your colon may be taken.
Sigmoidoscopy using a rigid scope may be done to treat problems of the anus or rectum.
Your doctor or nurse will tell you how to prepare for the exam. You will use an enema to empty your bowels. This is usually done 1 hour before the sigmoidoscopy.
On the morning of the procedure, eat a light breakfast.
During the exam you may feel:
After the test, your body will pass the air that was put into your colon.
Children may be sedated for this procedure.
You doctor may recommend this test to look for the cause of:
This test can also be used to:
A normal test result will show no problems with the color, texture, and size of the lining of the sigmoid colon, rectal mucosa, rectum, and anus.
Abnormal results can indicate:
There is a slight risk of bowel perforation (tearing a hole) and bleeding at the biopsy sites. The overall risk is very small.
Reviewed By: George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, and Stephanie Slon.