Flexible sigmoidoscopies examine the rectum lining and part of the colon. The GI doctor enters the flexible tube through the anus to the rectum and lower part of the colon. The doctor examines the lining of the intestine as they carefully withdraw the instrument. If your doctor finds polyps, they may take a tissue sample for biopsy. Some polyps are harmless but others may become cancerous.

The purpose

Flexible sigmoidoscopy allows the doctor to examine the rectum lining and the colon. Your GI doctor is also able to take tissue from the lining of the colon for a biopsy if any abnormalities arise.

This is a common procedure that allows your doctor to check for ulcers or abnormal cells.

Prepare for the procedure

Follow your doctor’s instructions when preparing for this procedure.  To prepare, your doctor could ask you to undergo one or two enemas—the process of infusing liquid or gas into the rectum to clear out the contents—or have you take laxatives and modify your diet. The goal is to have a clear rectum and lower colon for your procedure.

Check with your doctor about your current medications. Prescriptions and over-the-counter medications should be disclosed to your doctor, especially aspirin and blood-thinning medications. Inform your doctor of any allergies to medications.

What to expect

The procedure is performed by inserting a flexible tube with a light on it into the anus towards the rectum and lower portion of the colon. It is almost always an outpatient procedure and typically takes less than 15 minutes.

Patients find the procedure tolerable. Your doctor will ask you lay on your side as they insert the sigmoidoscope through the rectum and into the lower part of the colon. Your doctor will examine the intestine lining as they remove the scope.

Growths on the lining of the colon, called polyps, may be found during the procedure. Some polyps do not require removal while others have a small risk of becoming cancerous. Biopsies may be performed if your doctor finds something that they want to evaluate further. The biopsy isn’t painful. Doctors will typically perform a biopsy even if they don’t suspect cancer. If they determine that the polyps need to be removed, your doctor will schedule a colonoscopy to examine the entire colon.

After the procedure

The results of your sigmoidoscopy will be explained by your doctor following the procedure. Your normal activities and diet can resume after your procedure, with your doctor’s permission.