Describe the diagnostic approach.
If clinical suspicion is high : perform an enema.
If the diagnosis is unclear at presentation or pathological lead points are suspected : perform an ultrasound or abdominal x-ray to confirm the diagnosis.
List appropriate diagnostic procedures with theire respective findings (ultrasound, x-ray, ct).
Abdominal ultrasound (best initial test): often sufficient to confirm diagnosis
Target sign (transverse view): The invaginated portion of bowel appears as rings on a target in transverse view on ultrasound.
Pseudokidney sign (longitudinal view): The lead point of the invagination in the distal loop of bowel resembles a kidney. This “pseudokidney” is made up of longitudinal layers of bowel wall. 
Possible pendulous peristalsis
Can help rule out other causes of an acute abdomen
Contrast or pneumatic enema using ultrasound or fluoroscopy (best confirmatory test)
Interruption of contrast or air at the site of invagination.
Pneumatic insufflation (air enema): air is injected into the intestines to create pressure.
Inhomogeneous distribution of gas with absence of air at the site of invagination (usually right upper and lower quadrants) may be visible.
In cases of advanced-stage intussusception, other features of mechanical bowel obstruction will be detected.
Abdominal CT: Perform if ultrasound and abdominal x-ray are inconclusive.
May show target sign
Helps to identify pathological lead points
Laboratory tests: leukocytosis (suggests peritonitis)