Constipation is rare in infants breastfed, while receiving enough input, does not happen when the baby is fed infant formula or artificial feeding, provided it is adequate.
To think of a box of constipation, observe the characteristics of the stool, but the stools of a breastfed baby has loose stools so when this does not happen would have to consult your pediatrician.
We must remember that during the first three months of life, children move the intestines by reflex mechanisms or because the rectal ampulla filled triggering the deposition. This is because, in these early months, babies can not get your belly voluntarily to reflex mechanisms must resort to empty the bowel.
Different causes. If you still receive the proper diet, the baby should make an effort to evacuate their gut materialize we suggest an interview with the doctor so he can see that effort.
If the doctor confirms that it is more intense than usual, probably request a consultation to rule out obstruction tense or spastic anal sphincter. Or, as happens in rare cases to know that there is a megacolon (symptoms of this disease are different from what they say).
Another situation, more often than before, are anal fissures, some of which can not be seen to be located deep inside, making it difficult to diagnosis. However, this condition does not appear to be hereditary and probably will, allowing them to fully enjoy your baby.