EFFECT OF INFANT FORMULA ON STOOL CHARACTERISTICS OF YOUNG INFANTS

Background. Many infants are switched between multiple formula prepara tions early in life because of perceived abnormalities in stooling pat tern as well as gastrointestinal symptoms. Objective. To investigate t he relationship between the type of formula consumed and the stooling characteristics and gastrointestinal symptoms of young infants. Method s. Healthy 1-month-old infants were fed one of four commercial formula preparations (Enfamil, Enfamil with Iron, ProSobee, and Nutramigen) f or 12 to 14 days in a prospective double-blinded (parent/physician) fa shion. Parents completed a daily diary of stool characteristics as wel l as severity of spitting, gas, and crying for the last 7 days of the study period. A breast-fed infant group was studied as well. Results. Two hundred eighty five infants were enrolled and 238 completed the st udy. Infants receiving breast milk or Nutramigen had twice as many sto ols as other formula groups (P < .001). Infants receiving ProSobee had hard/firm stools more often than breastfed or other formula-fed group s (P < .00001). Watery stools were more common in infants fed Nutramig en than other formula groups (P < .04). Green stools were more common in 12 mg/L iron preparations (Enfamil with iron, ProSobee, Nutramigen) than in those with 1 mg/L (Enfamil, breast milk) (P < .00001). Spitti ng, gassiness, and crying were of equal severity in all formula groups . Conclusions. The interpretation of stool frequency, color, and consi stency must take into account the infant's formula type as significant variations in normal infants occur. Parental education on the range o f infant stooling characteristics as well as the common occurrence of spitting, gas, and crying may alleviate concern for formula intoleranc e and underlying gastrointestinal disease.