Esophageal obstruction following administration of "aged" barium sulfate tablets--a warning.

Esophageal obstruction was encountered in 2 patients following the adminstration of a barium sulfate tablet. The tablets did not disintegrate for over three hours. They had been stored in the radiology department for at least three years. In vitro tests showed that the old tablets did not disintegrate for three hours while fresh tablets disintegrated within 30 minutes.