What’s the Difference Between an Endoscopy, Colonoscopy and Sigmoidoscopy?
They are are procedures that use a scope to examine your insides and look for disease, but they have different uses.
A: Endoscopy is just a general term meaning we’re going to use a scope through one of your orifices to look at something inside of you.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Sigmoidoscopy and colonoscopy, and even esophagogastroduodenoscopy (EGD), are fancy words for different kinds of endoscopy. The –oscopy ending means you’re using a scope to look at something. And then the prefix of the word is what you’re looking.
So colonoscopy is a longer scope, and it can look all the way around the colon, which is about 6 feet long. In many cases, we can get through the little valve that connects your small bowel to your large bowel, down by your appendix, and also get a sneak preview at the very end of your small bowel. We do this to evaluate symptoms and to check for polyps or cancer.
A flexible sigmoidoscopy is essentially a shorter scope that we use to look at the lower part of your colon – so your anus, your rectum, your sigmoid colon and your descending colon. That’s about 70 cm. And occasionally, in certain people you can even get up to the transverse colon.
A proctoscopy or anoscopy (procedures to examine the inside of the rectum and anus), and even a flexible sigmoidoscopy, are less invasive and can be done in an office. But with colonoscopy, in general, you need to have a full bowel prep and some sedation.
— Colorectal surgeon Scott Steele, MD