What is the Difference Between Colonoscopy and Sigmoidoscopy?

The main difference between a colonoscopy and a sigmoidoscopy is the part of the colon they examine and the level of invasiveness. Here are the key differences:

• Colonoscopy: This procedure examines the entire large intestine, including the colon and rectum. It is more invasive than a sigmoidoscopy and requires a more complicated bowel preparation. sedation is usually needed, and the procedure is typically done every 10 years for people with average risk, starting at age 45.
• Sigmoidoscopy: This test is less invasive and examines only the lower part of the large intestine, including the rectum and sigmoid colon. It requires less preparation, and sedation is usually not needed. The procedure is typically done every five years for those with low risk for colorectal cancer.

Both procedures are screening tests used to look for colorectal cancer and other growths, such as polyps. If polyps are found during a sigmoidoscopy, a colonoscopy may be necessary to examine the entire colon. A colonoscopy is typically recommended for people with normal risk factors, while a sigmoidoscopy and fecal occult blood test can be an alternative option for those with low risk for colorectal cancer, along with a more frequent schedule of every five to 10 years for sigmoidoscopy and every year for the test.

Comparative Table: Colonoscopy vs Sigmoidoscopy

Here is a table comparing the differences between colonoscopy and sigmoidoscopy:

Both colonoscopy and sigmoidoscopy are nonsurgical procedures that involve the use of a tube (endoscope) with a light and camera to examine parts of the large intestine. However, they differ in the areas they cover, the level of invasiveness, the preparation required, and the frequency of the procedures.