What cause a bowel intercerception on a 5 year old boy ?

Look for lead point: The intussiception (telecscoping of bowel on itself) is an uncommon but worrisome event. It can arise spontaneously or due to a "lead point".There are lymph glands in the wall of the bowel that may produce an outward bump & a structure called a meckle's diverticulum can lead the process to form. If the process is reduced with a enema (not surgery), other studies may be done to look for a reason.

Intussusception?: If you mean intussusception there can be a few causes. An infection whether bacterial or viral can cause it. Also polyps, conditions such as cystic fibrosis or something called hs purpua. The child will usually have abdominal pain and perhaps red mucus stools. It is something you should get seen right away.