How is intussusception diagnosed in a child?

Rectal bleeding: Classic hallmarks of intussusception in a child are abdominal pain, lethargy and rectal bleeding (currant jelly stools). It is diagnosed with an air-contrast or barium enema. This xray study makes the diagnosis and in 80% of cases also cures the disease by reducing the intussusception.

Contrast enema: Intussusception is diagnosed by a radiologic study, a contrast enema, using barium or air for the contrast agent. In a majority of cases, the enema examination will not only be diagnostic but also therapeutic, achieving hydrostatic reduction of the intussusception and avoiding surgery. If the intussusception cannot be successfully reduced with the contrast enema, it must be approached surgically.