Table 6. Ancillary Tests in the Workup of Upper Gastrointestinal Bleeding in Children^{1,12,29,31,33}

Test	Description	Normal Result	Comments
Angiography	Arterial contrast study	No extravascular extravasation of dye	Has an overall good diagnostic rate of 64% but has better diagnostic accuracy in acute UGIB (71%) compared with chronic or recurrent UGIB (55%).
Apt-Downing test	Stool specimen from neonate	Negative	Important to distinguish between maternal and neonatal blood.
Endoscopy	Fiber-optic visualization of esophageal, gastric, and duodenal mucosa	No bleeding sites noted; no varices	Urgent endoscopy is indicated for bleeding requiring transfusion or hemodynamic instability; otherwise endoscopy can be performed within the first 24 hours of admission.
Gastric aspirate	Aspirate from nasogastric tube	No blood detected	Place nasogastric tube for gastric lavage to improve the accuracy of endoscopy. Consider testing gastric aspirate for occult blood using Gastrocult (Beckman Coulter, Inc., Palo Alto, CA).
Stool for occult/frank blood (eg, hemoccult)	Stool specimen from rectal examination	Negative	Alpha guaiaconic acid reacts with hydrogen peroxide in the presence of heme and produces a blue quinone compound. This denotes a positive test.