my 3.5yr old dd has completely regressed after her sister was born in june i know this is really common but i'm at wits end!! she's witholding wee and poo and refusing to sit on toilet has been really bad for a about 1 month i've tried ignoring it star charts rewards etc today i snapped and really shouted at her told her i was going to put her back in nappies if she didn't stop,all the things you're not supposed to do had to get my mum to come and get her because i felt close to the edge she particularly likes to do it when i'm seeing to the baby or the baby is crying she gets hysterical. i'm trying to stay calm and give her some attention but my nerves are v frayed. her speech has backtracked too and shes started getting out of bed at night!! now any advice?