False-positive results may be due to the following: A critical illness Receiving total parenteral nutrition and no oral foods (because gallbladder stasis prevents filling) Severe liver disease (because the liver does not secrete the radionuclide) Previous sphincterotomy (which facilitates exit into the duodenum rather than the gallbladder) Morphine provocation, which increases tone in the sphincter of Oddi and enhances filling, helps eliminate false-positive results.