Intussusception is the most common cause of intestinal obstruction and acute abdomen in the first year of life. Approximately in the 80% of cases intussusception occurs when the last ileal loop is pulled into the cecum, passing through the ileocecal valve, and finally resulting in the displacement of cecum in the upper abdominal. It could be related with mesenteric adenitis because enlarged lymph nodes, together with peristalsis, can serve as "lead point". Other forms of intussusception are ileo-ileal and colo-colic. The aetiology in infants and adults can be very variable and most often linked with secondary causes, such as benign or malignant lesions (polyps, tumors, lymphomas, intestinal duplication cyst, Meckel's diverticulum). In this paper we describe a rare case of idiopathic ileo-ileal intussusception in a 17 year old boy. We also discuss, with a careful analysis of the literature, the diagnostic and therapeutic protocol in case of intussusception ileo-colic approved at the Meyer Children's Hospital.