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A randomised controlled trial of contrast enhanced colonoscopy in the reduction of right sided bowel cancer.


People testing positive on a bowel cancer screening stool test are offered colonoscopy (bowel camera examination).

About half of those have cancers or polyps (small abnormal growths that might lead to cancer in the future) found on colonoscopy. Studies have shown that screening reduces cancer development (through removing polyps found) and deaths from cancer in the lower bowel.

However, in the upper bowel, the types of polyps often found (known as serrated) are flat, subtle and hard to find with standard colonoscopy and deaths from cancer of the upper bowel are not reducing.

Detecting polyps

Up to one in five bowel cancers may actually have developed from these subtle serrated polyps. Almost one in 12 bowel cancers found in England are missed despite a seemingly clear colonoscopy in the previous three years.

This study investigates if spraying a blue dye in the upper large bowel helps the doctor to detect more flat polyps during the colonoscopy.

At the moment, we do not know if spraying the dye in the upper large bowel is the best way to improve detection, so we need to randomly assign people who are due to have a screening colonoscopy into two groups, one to have a standard colonoscopy and the other to have a colonoscopy using the dye spray. We will then be able to compare what happens between the two groups.


Key facts

Start date 18 Jun 2019
End date 1 Dec 2025
Grant value £2,243,615
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