Sir.—From 1978 to 1980, there were several reports of lactobezoars in infants. Previously, this was considered to be a rare phenomenon. At that time, one of us (L.A.B.) was a member of the Committee on Nutrition of the American Academy of Pediatrics, and under their auspices, we sent a questionnaire to 100 nurseries in the United States, as well as to the formula manufacturers. Fifty-five nursery directors and all of the formula manufacturers responded. Of these, a total of 72,000 low-birth-weight infants were reported, 60 of whom had lactobezoar formation. All of the formulas then in use were found to have been fed to some infants in whom lactobezoars developed.
While few of the infants fed whey-predominant formulas were involved, and no infants fed human milk were involved, the whey-predominant formulas had been fed to comparably fewer of the infants in the total series. We concluded that some other