Flexible Sigmoidoscopy for Bowel Cancer Checks

A flexible sigmoidoscopy is a test that looks inside the rectum and lower part of the colon. It may be used to investigate symptoms, check abnormal findings or screen for colorectal cancer in some settings.

This article is for general information only. Your doctor can explain whether flexible sigmoidoscopy is suitable for your symptoms or screening needs.

What Is Flexible Sigmoidoscopy?

Flexible sigmoidoscopy uses a thin, flexible tube with a light and camera. The tube is gently passed through the anus into the rectum and lower colon so the doctor can look for polyps, inflammation, bleeding or abnormal areas.

Unlike colonoscopy, flexible sigmoidoscopy does not examine the entire colon.

Why the Test May Be Done

The test may be used if someone has rectal bleeding, bowel habit changes, abnormal screening results or symptoms involving the lower bowel.

Flexible sigmoidoscopy can be one of several colorectal cancer screening options. CDC notes that if flexible sigmoidoscopy has a positive or abnormal result, colonoscopy is needed to complete the screening process. :contentReference[oaicite:5]{index=5}

How to Prepare

You may be asked to use an enema before the test to clear the lower bowel. Some people may also receive specific diet or medication instructions.

Follow the instructions from your clinic carefully. If you take blood thinners, diabetes medicines or have serious medical conditions, tell the medical team in advance.

What Happens During the Test?

You may lie on your side while the doctor gently inserts the scope. Air may be used to open the bowel so the lining can be seen more clearly. This can cause pressure, cramping or wind.

If an abnormal area is seen, a small biopsy may be taken. Some polyps may also be removed depending on the situation.

After the Test

After flexible sigmoidoscopy, you may feel bloated or pass wind. If a biopsy was taken, you may notice a small amount of bleeding. Your clinic will explain what is normal and what symptoms need medical advice.

For more testing information, read our Tests to Find Cancer in the Bowel article.