Intussusception is a rare but serious disorder in which part of the intestine — either the small intestine or colon — slides into another part of the intestine. This "telescoping" often blocks the intestine, preventing food or fluid from passing through. Intussusception also cuts off the blood supply to the part of the intestine that's affected.
Intussusception is the most common cause of intestinal obstruction among children. Intussusception is rare in adults. Most cases of adult intussusception are the result of an underlying medical condition. In contrast, most cases in children have no known cause.
Emergency medical care is required to treat intussusception to avoid severe dehydration and shock, as well as prevent infection that can occur when a portion of intestine dies due to lack of blood. With prompt attention, intussusception can often be successfully treated without lasting problems.