The bowel movement characteristics of exclusively breastfed and exclusively formula fed infants differ during the first three months of life.

AIM: Breastfed infants pass more stools and more liquid stools than formula fed infants and some have no bowel movements or infrequent stools for several days or weeks. We compared exclusively breastfed and exclusively formula fed infants for the first three months.

METHODS: This study of 118 infants was carried out in the maternity ward of the Lille University Jeanne de Flandre Hospital, France, in 2015. The outcomes were the number and consistency of stools and the prevalence of infrequent stools.

RESULTS: At three months, 84 infants remained and we compared 40 who were exclusively breastfed and 13 who were exclusively formula fed. Daily stool frequency was significantly higher in the breastfed than formula fed infants during the first (4.9 ± 1.7 vs. 2.3 ± 1.6, p < 0.001) and second (3.2 ± 1.6 vs. 1.6 ± 1.5, p = 0.003) months. Stools were more liquid in the breastfed infants during the first three months. Infrequent stools occurred in 28% of breastfed and 8% of formula fed infants at least once. (p = 0.25).

CONCLUSION: Exclusively breastfed infants produced more stools than exclusively formula fed infants during the first two months and more liquid stools during the first three. Infrequent stools were 3.5 times more likely in the breastfed infants.