Mommy has a surprise for Caillou: a potty for him to use. No more diapers. Caillou's a big boy now. After several attempts, a few failures and near-misses, Caillou learns to ask for the potty when he needs it. Toilet training is an important step in child development. Adults are in a hurry, toddlers have lots of time, but it is essential to respect their own internal rhythm. Children must acquire bowel and bladder control of their own free will.