She quite often goes the entire day without going to the toilet. I asked her tonight if she had been to the toilet today (this was at 6pm) and she said no! She then went when I asked her to and weed/pooed. She goes most days at school without going to the toilet and will only go once we get home if I remind her or under duress. She's not a big juice/water drinker and will not be persuaded to drink more than she already does. Not surprisingly, her nappy in the morning is normally huge and saturated. How do I sort this out? Is it a psychological thing or just a bad habit?