Hi, my 4.2 mo old ds is seeing a peadatrician on tues, for reflux, & i need to take a urine sample. I've been given a bottle & something in a sterile packet. I dont want to take it out of its packaging til tues am, what exactly do i do with it. Obv i know you need to collect urine with it, it looks like you put it in his nappy. Any ideas/help? Many thanks.