Epidemiology of bladder stone of children: precipitating events.

Urological surgery evolved from the ancient practice of removing primary bladder stones from young boys. Bladder stones, once ubiquitous, long ago disappeared from the developed world while pockets of disease still exist in developing countries. Two epidemiological studies identified as precipitating events of bladder stone formation the practice of substitutive carbohydrate feedings to newborns. In Southeast Asia, masticated rice is fed to newborns in stone-endemic villages while in England, during the eighteenth and nineteenth centuries pap or panada was used to hand-feed infants when breast milk was not available. Fresh milk from dairy animals was deemed preferable to pap. Lack of access to dairy cattle enhanced need for hand-feeding. In an epidemiological study, during mid-nineteenth century in England the prevalence of dairy cattle was inversely related to the prevalence of bladder stones. These epidemiological data relate stone formation to nutrition during the first few days or weeks of life. It is surmised that frequent use of or exclusive reliance on carbohydrate foods replacing milk feedings leads to a relative dietary deficiency in phosphates and the formation of insoluble urinary salts. Girls, with short, nontortuous urethras may pass much of the calculus debris without retaining nuclei in the bladder. In some males, stone nuclei are formed and retained. The growth of stones is determined thereafter by the net effect of depository and resorptive mechanisms operating over time distributing over many years the age that patients present for surgical stone removal. The role of early introduction of carbohydrate foods and reduced milk intake of neonates has not been incorporated into recommendations for feeding newborns in endemic countries nor comprehensively modeled in animals.