My one month old is constipated could it be the milk?she's taking enfamil for infants the yellow can and is pooping very hard and crying

Could be: Constipation in infants can occur if they are having trouble digesting certain components in formulas. Make sure you are mixing it properly, as concentrated formulas can also cause constipation.

Infant constipation: One month old infant on formula sometimes has constipation. Add a teaspoon of 100% prune juice once a day would help. Lactulose 10g/15 ml could help too. Dose is 2.5 ML to 10 Ml a day by mouth ( you can put in the infant formula and give it to the baby. Try prune juice first. Good luck !!!