Hi I Am The Mother Of 3 Boys, My Middle

Hi I am the mother of 3 boys, my middle child was potty trained to pee and poop on the potty since he was 2 he is now almost 8. He recently started to play in his poop. He is clean when he goes to bed but appartly he pulles the poop out from his rectum area. He then smears it like its toothpaste. On one occasion he used it to put hold a poster up. We are an extreamly clean so the smell is very strong. What do i do the Dr we see said it was a sensory issue. Not sure I'm with him all the way on that one. Any advice for me. Its getting awful smelly in our house making most of us to so happy. Jennifer