Introduction Patients with a positive faecal occult blood test in the BCSP are invited to undergo an alternative radiological colonic investigation if deemed unsuitable for colonoscopy. CTC, a radiological modality of choice at St Mark's, is less invasive than optical colonoscopy but there are conflicting data regarding relative patient experience. Approximately two thirds of patients having colonoscopy in our centre are sedated with a combination of midazolam and pethidine compared to CTC, which is an unsedated procedure. The aim of this study was to compare patient experience of those undergoing CTC vs colonoscopy within the BCSP.

Methods We retrospectively reviewed our local screening centre's database from September 2008 to November 2009 to determine the number of patients who had undergone CTC within the BCSP and had also completed and returned a standard 30-day questionnaire (routinely sent to all patients following their secondary examination within the BCSP). The questionnaire includes four domains assessing experience before, during and after the procedure and also overall level of satisfaction. Completed questionnaires were then compared to an equal number of age and sex matched consecutive patients who had undergone optical colonoscopy during the same time period. Fisher's exact test was used to compare responses.

Results 21 (10 male, mean age 67 years, SD 4.7) of 83 patients undergoing CTC completed and returned a questionnaire (response rate of 25%), which is significantly lower than colonoscopy response rate of 72% (756 of 1057 patients) (p<0.0001) for the similar time period.

There was no significant difference between patient groups with respect to pre-procedure experience or overall satisfaction. However, CTC patients reported more discomfort than expected (8/21 vs 0/21, p=0.003) and only 4/21 (20%) had no or less discomfort than expected compared to colonoscopy (13/21, 62%, p=0.003). CTC patients were also more often discharged without knowing the result of the procedure (10/21 vs 2/21, p<0.001) and were less likely contacted by screening practioners afterwards (13/21, 68% vs 20/21, 95%, p=0.04).

Conclusion Discomfort during CTC is higher than patients expected and post examination communication is inferior, also reflected by lower questionnaire response rates. While colonoscopy sedation and use of a questionnaire designed for colonoscopy may be confounders, the authors conclude that centres should re-examine the quantity and quality of patient information provided for CTC by screening practitioners. We also recommend a larger prospective multicentre study to compare experience, using a more detailed and less “technique specific” questionnaire.