Comparison of Bowel Preparation in Virtual Colonoscopy (VC) - Patient Experience

• Versus standard bowel preparation [ Time Frame: 1 day (while on regimen + effectivness analysis time) ]
• Patient experience and compliance with reduced laxative tagging versus standard preparation [ Time Frame: 1 day (while on regimen) ]

• versus standard bowel preparation
• Patient experience and compliance with the reduced laxative tagging regimen

The study will compare patient's experience between those taking a standard bowel cleansing regimen with minimal laxative tagging regimen of senna and gastrofin. Additionally comparing any possible reduction in diagnostic accuracy that may ensue from an increased quantity of retained faecal residue.

Bowel cleansing with high dose laxative is the standard bowel preparation prior to whole colon investigations but such regimens are associated with considerable patient discomfort and inconvenience, potentially affecting compliance rates [1-3].

Unlike existing whole colon investigations (conventional colonoscopy and barium enema), reduced laxative regimens can be successfully used with VC, with the aim of improving patient experience, whilst maintaining diagnostic accuracy. These regimens utilize faecal tagging; a method of labeling residual faeces and fluid with radiodense liquids, such as iodine or barium based fluids, which are taken orally by the patient. Once faecal residue and fluid is labeled in this way, it can easily be discriminated from true pathology (which remains 'untagged').

We are proposing to compare different bowel preparation regimens, and ascertain patient experience of the different regimes, while monitoring diagnostic accuracy of the 2 different regiments.

• Active Comparator: 1 A
  gastrofin & Picolax
  Intervention: Drug: bowel preparation: senna & gastrofin versus picolax (standard)
• Active Comparator: 2
  senna
  Intervention: Drug: bowel preparation: senna & gastrofin versus picolax (standard)

Inclusion Criteria:

• patients with symptoms attributable to colorectal cancer

Exclusion Criteria:

• patients with known colorectal cancer referred for staging VC
• patients who take laxatives regularly or with previous inadequate colonic examination due to excessive faecal residue
• patients deemed too frail to undergo full bowel preparation