My son is going to a therapist and I thought she would be able to tell usthe reason why he will not go bm in toilet. It doesn't matter if he is wearing a diaper or underwear he will still soil himself. We never forced him to sit on the toilet. The therapist says to keep reminding him for he has to learn to go and it doesn't work. Keep him on a schedule and remind him. Is not working. He is intelligent otherwise and has friends in school.