Diagnostic Ba enema is not a substitution for a well executed physical examination, and its use should be reserved only for obscure situations. An abnormal roentgenogram provides valuable information, since the fear of missing acute appendicitis in these children is minimized. When normal, this diagnostic test may bring to early operation those with minimal symptoms or unusual presentations, thus avoiding the possibility of prolonged observation and perforation. In children with known associated severe medical maladies, diagnostic Ba enema can serve to reaffirm the diagnosis prior to the hazardous operative intervention. It may also eliminate the need for operation in those conditions which mimic acute appendicitis. The use of diagnostic Ba enema in the past 3 1/2 yr significantly improved diagnostic capabilities in children with abdominal pain. There was a corresponding reduction in the number of normal appendixes removed. The efficacy and, above all, the safety of this procedure make it a valuable diagnostic aid in the care of children.