Hello, I have read your question and understand your concerns. Crayons are usually made up of wax, however you should read the information on its packing to know any harmful ingredients. Small amount of wax usually passes out of system of child without causing any problem. However cases of intestinal obstruction in children due to wax are reported. You need to observe your child. If he remains symptoms free, there is no need to worry. But if his condition worsens, you need to see your Pediatrician for further advise. Hope your query has been answered.