My (nearly) 4 year old still has accidents in his underwear. He went through a really great stage where he was using the toilet with no accidents, but all of a sudden, its all gone out the window. He frequently has accidents and doesn't say anything. Yesterday, he did a poo and was playing wiht it in his pants so it ended up all over his hands and clothes. Its so frustrating, because he was doing it perfectly. Any ideas?