The results of the radiological examination of 330 children following oral administration of barium are reported. It is pointed out that if one just takes into account the undoubted organic diseases, only a few children would benefit from the examination; in our case only 9 of them (a gastric and a duodenal ulcer, a pancreas pseudocyst, 5 hiatal hernias, and a celiac disease), i.e. 3%. This is not very satisfactory from a practical point of view. This situation improves radically when one looks for diseases usually rated as questionable: small hiatal hernia (cardiotuberositary malposition), functional disturbances of the small intestine, reactive hyperplasia of the lymphoid tissue, and chronic appendicitis. Thus we were able to offer 177 children, i.e. 53% of them, an efficacious therapy. The importance of chronic appendicitis and of functional disturbances of the small intestine as a cause of abdominal pain in children is pointed out, and their radiological symptoms are discussed. Finally the not uncommon, but not very well known disease of incomplete sigmoid volvulus is described.