What is a sigmoidoscopy?
A sigmoidoscopy is a test that looks at the inside of the rectum and the part of the colon closest to the rectum (the sigmoid colon). You usually have it as an outpatient, so you can go home the same day.
Types of sigmoidoscopy
There are two types of sigmoidoscopy:
- Flexible sigmoidoscopy. This is used to check the rectum and sigmoid colon.
- Rigid sigmoidoscopy. This is used to check the rectum and anus.
What is a sigmoidoscopy used for?
A sigmoidoscopy is used to check the inside of the rectum and the sigmoid colon to look for any abnormal areas. It can help to diagnose bowel cancer.
The term bowel cancer is normally used to talk about colon cancer and rectal cancer.
Cancer that starts in the colon or rectum is also sometimes called colorectal cancer.
Related pages
What happens during a sigmoidoscopy?
For a sigmoidoscopy, you lie curled up on your left side. A doctor or nurse passes a tube into your rectum. This tube is called a sigmoidoscope. It has a light and camera on the end.
A small amount of air is pumped into the bowel to make it easier to see inside. This will make you feel like you need the toilet, but the feeling will gradually go away once the test is over.
During the test, the doctor or nurse takes biopsies from any areas of the colon that look abnormal. This is painless.
You should be able to go home as soon as the test is over.
Related pages
About our information
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.
-
References
Below is a sample of the sources used in our bowel cancer information. If you would like more information about the sources we use, please contact us at
informationproductionteam@macmillan.org.uk
National Institute for Health and Care Excellent (NICE). Colorectal cancer. NICE guideline [NG151]. Updated December 2021. Available from: www.nice.org.uk/guidance/NG151 [accessed Jan 2023].
Cervantes A, Adam R, Rosello S, et al. Metastatic colorectal cancer: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up. Annals of Oncology. 2023;34(1):10-32. Available from: www.annalsofoncology.org [accessed Jan 2023].
Date reviewed
Our cancer information meets the PIF TICK quality mark.
This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.
The language we use
We want everyone affected by cancer to feel our information is written for them.
We want our information to be as clear as possible. To do this, we try to:
- use plain English
- explain medical words
- use short sentences
- use illustrations to explain text
- structure the information clearly
- make sure important points are clear.
We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.
You can read more about how we produce our information here.