I used these with both of my boys. My oldest son never had any problems with it. Super easy to use, very versatile, being that you can use it for a step stool for little hands to use the sink and removable part to put on the toilet seat for tiny bottoms. It was great first time around. Then with my next son, he is a shorty and I don't know it thats the problem or its the seat, but when he sits to go number two, it always pinches his legs. Always. So we had to teach him to just put the removable seat onto the toilet, then use the step to get up on it and not be scared. It was scary for him at first. But it may just depend on the child. But he never could sit down on it.