I haven't got enough stool in the tubes, will that make a difference to the test?

As long as top of the sample hits between the 'min' and 'max' lines, it will be fine.

If you're worried your sample tubes aren't full enough, check that the top of the sample reaches between the 'min' and 'max' lines.

If it doesn't, it's fine to 'top up' the tubes with stool from another bowel movement, if it's on the same day.

If you can't do that, let customer services know and they'll send you out another kit.