Before I attempt to answer this, let me make sure I understand the question. Are you saying that most children are fascinated in throwing up themselves, or are they fascinated in "throw up", possibly by another child? There is a great difference. Children are fascinated in throwing up like they are in farting or burping. Itis a natural occurance, but because of the seemingly violent or extreme action that occurs, they tend to wonder about it. It usually brings out every type of reaction, from a giggle to outright crewd remarks. If the fascination is just that, I wouldn't worry about it. If the fascination is causing them to make themselves throw up, just to feel the effects or to see what comes up, then there is a problem. This experience might help illustrate my point: A few years ago, my ten-year old daughter was taking a dance class. During one of the practices, she attempted to do a front roll. She extended her arms, but instead of rolling, she landed with her whole body weight on her arm and it broke. A week after going to the hospital and getting the cast, she was able to attend school again. One of her friends saw the cast and was envious of the attention she got from it. She said, "You are so lucky to have a cast. I want a cast, too." That very evening, her friend, according to what she told my daughter, intentionally fell on her arm, broke it, and was taken to the hospital for the cast. When she, herself, returned to school, she immediately ran up to my daugter and told her what she did. "Look, I've got a cast just like you do now." That girl's mother needed to know why she broke her arm. That is a serious problem!