Intussusception is the telescoping of a proximal segment of the bowel into the lumen of an adjoining distal segment.
Needless to say, there is a grave risk of cutting off the blood supply to the gut and developing gangrene. It is common in children. Ileocolic, colocolic, and ileoileal forms do occur, but ileocolic is the most common. The high incidence in children may be caused by the relatively large size of the large bowel compared with the small intestine at this time of life. Another factor may be the possible swelling of Peyer’s patches secondary to infection. In the latter case, the swollen patch protrudes into the lumen and violent peristalsis of the ileal wall tries to pass it distally along the gut lumen.