Barium enema

If you had an abnormal FOB test, but aren't able to have a colonoscopy or CT colonoscopy, you may be offered a barium enema instead, although these are rarely needed.

This is a special x-ray of the large bowel. It's important that the bowel is empty so that a clear picture can be seen. You'll need to follow a special diet before the test and your hospital will give you information about this.

What happens?

During the procedure, a mixture of barium (which shows up on an x-ray) and air is passed into the back passage using a small flexible tube. It's important to keep the mixture in the bowel until all the x-rays have been taken. The doctor can then watch the passage of the barium through the bowel on an x-ray screen and look for any abnormal areas.

A barium enema takes about 30 minutes and can be uncomfortable and tiring, so it's a good idea to arrange for someone to travel home with you if possible.

For a couple of days after your enema, you may notice that your stools are white. This is the barium being removed from the body and is nothing to worry about. The barium can also cause constipation and you may need to take a mild laxative for a couple of days afterwards.

Waiting for test results

It will probably take several days to a couple of weeks for the results of your tests to be ready. Waiting for results can be a difficult time and you may need support from one of our cancer support specialists.

Back to Bowel screening

The bowel

The bowel is part of our digestive system and is made up of the small bowel and the large bowel.

What to do with your FOB test kit

This test checks bowel motions for tiny amount of ‘hidden blood’. It is not a test for cancer, but can indicate whether further tests are needed to examine the bowel.


A colonoscopy is a way of examining the lining of the bowel from the inside.

CT colonography

This test uses a CT scanner to create a picture of the bowel.