A critical analysis of the routine testing of newborn stools for occult blood and reducing substances.

Stool tests for occult blood or reducing substances were introduced in the neonatal intensive care unit (NICU) as potential aids in the early recognition of necrotizing enterocolitis (NEC) in high-risk neonates, and have been recommended by some as routine nursing procedures. Neither the performance characteristics of these tests with respect to NEC, nor their indirect impact, were evaluated formally before widespread adoption into clinical care. The published evidence suggests that these tests are not useful as diagnostic or screening tools.