An 8-year-old boy was hospitalized for recurrent painless bleeding. Tc-99m pertechnetate scintigraphy showed a peculiar pattern. At surgery, an interesting duplication with cystic dilatation and perforation was found. Tc-99m pertechnetate scintigraphy is used frequently to detect Meckel diverticulum in infants with lower gastrointestinal bleeding, because pertechnetate is concentrated actively by the gastric mucosa contained in some diverticula. Other conditions such as intestinal duplication with ectopic gastric mucosa also can be identified using this method.