I have a fair bit of experience! There are sticky bags they can provide which work particularly well for boys, but don't tend to give a clean catch Just to have a sample dipped for blood/pus it's sufficient to put a ball of cotton in the nappy to squeeze out To get a proper sample though, you need to do it when they are asleep, or if feeding/cuddling for a particularly ill/floppy child TSke off nappy TSke sterile shallow bowl Place conti pad or waterproof bed sheet on your lap Sit child on your lap, feed, cuddle to sleep, distract with tv or story Hold bowl below child with spare hand Pay attention A warm feeling in your lap means there is wee to catch You need just a tiny bit Good luck!