In early stages it is difficult to palpate the abdominal mass particularly if the child is active and crying. Tip of intussusceptum may be felt some times on rectal examination. This does not necessarily indicate long standing intussusception and irreducibility, such a presentation may mean that colon is more mobile. A plain x-ray abdomen may show absence of caecal gas shadow in the right iliac fossa, or obvious features of intestinal obstruction. In many cases one can not be certain of intussusception from clinical features even if complemented by plain abdominal x-ray.
Barium enema is the gold standard in diagnosis.
It will clearly demonstrate obstruction of the colon, and classical claw sign due to the filling defect created by convexity of the intussusceptum can be seen. However, barium involves radiation and is time consuming for it to be used routinely in all suspected cases. It is also not helpful if intussusception is involving small bowel only. The main role of barium enema is in hydrostatic reduction. Ultrasound is a useful adjunct for screening all suspected cases of intussusception.