A study to find out what people think about having a CT colonoscopy

Cancer type:

Bowel (colorectal) cancer





This study was done to find out what people thought about the different ways to prepare for a bowel cancer test called a CT colonography.

If your doctor thinks you could have bowel cancer, you may have a test called CT colonography, or virtual colonoscopy. This gives the doctor 3D pictures of what the bowel looks like inside, without using a camera to look inside the bowel (colonoscopy).

Before the scan you need to take laxatives and plenty of fluids to clear out your bowel. And you follow a special diet for a couple of days beforehand. Doctors call this bowel preparation. But if your doctor thinks that your body will not be able to cope with strong laxatives, they may ask you to drink a liquid called barium in the days before your scan instead. Barium makes your stool (faeces) show up on the scan differently to cancers or pre cancerous growths (adenomas).

The aim of this study was to find out what people thought about the scan and the different types of bowel preparation.

Summary of results

The research team found that people who had barium before their scan found it more acceptable than those who had laxatives.

The research team phoned 18 patients at least 3 days after they’d had the CT colonography. Of these, 9 had had the laxative preparation, and 9 had had the non laxative preparation.

Those who’d had the laxative preparation had diarrhoea that was bad enough to affect their daily life. This group also found the recommended diet changes difficult, and were often hungry.  When they got to the hospital they needed to drink a liquid to help the bowel show up better on the scan. Then they had to wait at the hospital for 2 hours before they could have the scan, which they didn’t like doing. Some people also continued to have diarrhoea in the days after the scan.

Overall the people who had the laxative preparation felt that having the laxative was a negative experience.

The research team found that those who’d had the non laxative preparation had less disruption to their daily life, and found the diet changes easier. They didn’t have to wait as long at the hospital, and tended to recover more quickly. They didn’t have any diarrhoea after the scan. Overall people found the non laxative preparation a less negative experience than those who had the laxative preparation.

Some people who took part in this study didn’t fully understand why they had the preparation they did. The research team recommend that patients having this test are given better information to explain it.

The research team concluded that having non laxative preparation for a CT colonography was more acceptable than having a laxative preparation.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Steve Halligan

Supported by

Department of Health
NIHR Programme Grants for Applied Research (PGfAR)
National Institute for Health Research Cancer Research Network (NCRN)
University College London (UCL)

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 8984

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Alan took part in a clinical trial for bowel cancer patients

A picture of ALan

“I think it’s essential that people keep signing up to these type of trials to push research forward.”

Last reviewed:

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