What is a Sigmoidoscopy?

A flexible sigmoidoscopy is a procedure that a doctor closely examines the lower parts of the colon, more specifically the sigmoid and descending colon, for signs of cancer or polyps. Polyps are small growths that have the potential to become cancerous.

The doctor uses a thin, flexible, lighted tube with a tiny camera at the end, called a sigmoidoscope, to thoroughly examine the colon. The examination usually takes 10 to 20 minutes and medication is usually not required.

Why a Sigmoidoscopy?

A flexible sigmoidoscopy allows a doctor to examine the possible causes of abdominal pain, rectal bleeding, chronic diarrhea, and intestinal problems. A sigmoidoscopy is also useful for screening for colon cancer and polyp growth.

Preparing for a Sigmoidoscopy

Patients will be given specific instructions to prepare for their scheduled sigmoidoscopy. These instructions will include a special diet the day before and day of the procedure, as well as detailed instructions regarding medication. A clear liquid diet is usually the designated diet before a colonoscopy.

During your Sigmoidoscopy

Steps will be taken to ensure that you will be as comfortable as possible. Sedation is not usually necessary. Lying on your side, the doctor will insert the sigmoidoscope into your rectum and examine the lining of the colon with the attached light and camera. Abdominal cramping or the urge to have bowel movements are common effects of the sigmoidoscope. A flexible sigmoidoscopy exam usually takes 15-20 minutes, but will require more time if biopsies are taken.


Mild abdominal discomfort and feeling bloated/passing gas are common effects after the exam. This tends to disappear after a few hours. You can return to your normal diet and activities right away. A small amount of blood in your first bowel movement is also a common occurrence and should not cause any alarm. If you continually pass blood, have persistent abdominal pain, or develop a fever contact your doctor for further advice.