 The randomised study from The Netherlands demonstrated that the diagnostic yield of advanced neoplasia cancers and significant adenomas per 100 invitees was greater for FS than for either of the faecal tests suggesting that the overall performance of FS may be better than faecal testing despite a lower participation rate. This introduces an important ethical dimension; namely, whether or not it is acceptable to use a population screening tool that reaches a relatively small proportion of the population rather than a test that is associated with a higher participation rate but has an overall poorer performance in terms of disease detection. This is further complicated by the adverse effect of deprivation on uptake of screening. It is known that, in Scotland, the difference in uptake of gFOBT population screening between the most deprived and the least deprived quintile is around 20. The effect of deprivation on uptake of FS population screening is not known, although in the UK FS trial there was a 16 difference in intention to participate and a 20 difference in actual uptake in those invited between the most and least deprived quartiles in Glasgow. 