DS has been doing really well with potty training, only had a couple of accidents in past 10 days or so but last night he had some sort of tummy bug and vomited his little guts out from 7 to 11pm :-( 8am this morning he told me he needed to wee and did a huge pee on the potty, at about 10 am I found a puddle where he'd obviously gotten pants off but not made it to loo / potty but he hasnt pee'd since then and it's now 5pm!! He has had a little to eat, two drink bottles of water, around 500 / 600 mls I guess. I've put him on the potty several times and he insists no wee's coming. He's very tired and lethargic but not been sick today. Was in pull up for nappy but I think it was dry after - at what stage do I worry????