[Blood in the feces as an aid to the diagnosis of necrotizing enterocolitis].

The presence of macro or microscopic blood in the stools of 300 premature babies was studied prospectively in relation with the future risk of necrotizing enterocolitis (NEC). The microscopic blood was investigated using the bililabstix reactive stripe. Four group were made up: group A babies, with no blood in their stools. Group B babies with microscopic blood in feces. Group C babies with macroscopic or gross blood and group D babies with initially microscopic and later gross blood in their feces. The frequency of NEC for these groups were as follows: group A 0.0%, group B 0.47%, group C 63.3% and group D 89.6%. We conclude that it is possible to predict absence of manifestations of NEC when a premature baby does not show gross blood in the stools during the first 21 days of life. When the babies show gross blood in the feces, the frequency of NEC is 63.3% and the higher frequency (89.6%), belongs to the babies with initially microscopic and later gross blood.