My son will be five in March and flatly refuses to poo in the toilet. Every night, he gets a nappy on and within 5 minutes, is dirty. I have tried not putting the nappy on, but he just holds it in and has managed 3 nights running before I gave in fearing that this could cause more problems. He wees in the toilet with no problems at all, hasn't even had an accident in over a year. He's embarrassed by it, and won't discuss WHY he does this, only promises that NEXT time, he'll use the toilet, but never does. His 3 year old sister uses the toilet properly, and I have tried praising her in his presence, and also offering bribes/rewards, but to no avail. As far as I am aware, he has never had a bad experience with the toilet.I am hoping that he'll just suddenly start using the toilet, but my husband is getting increasingly stressed out by it and I would be so grateful for any advice anyone might have.