Urea salvage in a neonate with cloacal exstrophy.

Urea kinetics were measured in a child with congenital absence of the colon on days 15, 19, and 23 of age. Urea salvage was 5% of urea production in the first study, increasing to 79% by the third. This provides evidence that the colonic microflora play a more active part in urea salvage than the mucosa and that the establishment of an active lower ileal microflora takes over some of the metabolic functions of the intact colon.