The Bowel Cancer Screening program was implemented to address the important issue of prevention and early detection of bowel cancer. Results from the first few years of screening and previous smaller studies show that while in its current form it will save many lives, there continue to be polyps and cancers in the upper large bowel (right side) that may be difficult to detect. There is some evidence that these types of polyps (serrated polyps) may be at least partly responsible for cancers missed at the initial colonoscopy and have a faster rate of growth to cancer compared to conventional polyps (adenomas). We propose to examine participants undergoing screening colonoscopy with the addition of a contrast dye ( a safe food colouring agent base already used in various bowel camera procedures in standard clinical practice). This has been shown to improve detection of conventional polyps significantly even though it is considered by some to be more time consuming (possibly taking a few minutes longer) and requiring specific training to undertake. We hope to study the feasibility of undertaking these procedures to improve detection and removal of these polyps within the bowel screening program and potentially inform further studies to assess the impact of improved detection and consequent potentially reduced incidence of interval or missed bowel cancers in longer term follow up. Thus the main aims of this feasibility study are to assess if this type of procedure would be feasible to implement and acceptable to participants, colonoscopists and the screening program and also assess any additional time or costs involved to inform the question of if a larger study should then be undertaken to conclusively prove or disprove the merits of this approach in terms of health economics, cancer detection and survival.

Inclusion Criteria:

• All participants testing positive on Faecal Occult Blood Test (FOBT) in the screening program who are eligible and appropriate for an index screening colonoscopy will be offered participation in the study.
• All participants attending for a one year surveillance colonoscopy if they have undergone an index screening colonoscopy as part of the study as per current guidelines for surveillance will also be offered inclusion

Exclusion Criteria:

• Any participants not deemed fit for colonoscopy on the screening program or undergoing alternative investigation such as CT Pneumocolon or minimal prep CT scan as their index procedure instead.
• Participants who have undergone previous colorectal surgery will be excluded from the study though their standard management in the screening program will continue unchanged.