What is a usual age for diagnosis of cf? my lil man is being treated as asthma but doesnt fit into the usual, every time the symptoms flare up he gets a pale clay coloured poo,(sorry for that) It is usually brown but floaty and smelly. This is not usual for asthma, but happens with every flare up and on his last admission had sats of 90% they stayed there for a few weeks after was discharged at 92%. He has sob and coughs like always seems to have something in throat. He had a sweat test when he was little that was not diagnostic? what does that mean? can you get a false negative result? Are there other things that i should request. He also has clubbed fingers and toes are starting to go.