My DS vomits on contact with paracetamol (every brand!) - don't know why, but he is 5 and it has always been the case. Every now and then if he needs it I will try oral and every time... straight back at me. He can't have ibuprofen due to other health issues. If he absolutely needs paracetamol I use the suppositories. Just make sure you use a generous amount of lubricant!!