A newborn’s first stool usually consists of a thick, black or dark green substance called meconium. It’s good that he’s passing this and getting it out of his system.
After the meconium is passed, the stools of breastfed infants look mustard yellow with seed-like particles, although they can also appear green. There is a lot of variation between babies on the number of times they have a bowel movement. A very soft, sometimes even watery, stool is normal for breastfed infants too.
Formula-fed stool is soft but better formed than the stools of breastfed babies. The color may range from yellowish-brown to light brown.
More than likely, your baby’s iron supplement or iron-fortified formula is making his stool dark green, dark brown or black. There’s no medical significance in this change and no need to be concerned.
DARK BROWN WITH VARIOUS COLORS:
When your baby begins eating solid food, his bowel movements might become dark brown—although seemingly odd colors are possible as well. For example, his stool might look red after he eats beets or might contain streaks of dark blue after he eats blueberries. Or you might also find chunks of undigested food in your baby’s bowel movements.
If the harmless causes have been eliminated (meconium, iron supplements), then black, tarry stool could indicate that there may be blood in your baby’s upper GI tract.
If the harmless causes (beets, food coloring) are not present, red streaks in the diaper may indicate blood in the stool. It’s better to check with your pediatrician than to worry about it.
If stool is white, then bile is not reaching the stool, either because it is not being made by the liver or because something is blocking it from getting to the small intestine.
- If your baby’s stool is consistently water, it might be diarrhea. Call your pediatrician if it lasts more than 24 hours.
- If your baby is consistently producing dark, hard stools, this could be a result of several causes. Contact your pediatrician.
Bekkali N, et al. J Pediatr. 2009;154:521-536.
den Hertog J, et al. Arch Dis Child Fetal Neonatal Ed. 2012;97:F465-F470.
Hyams JS, et al. Pediatrics. 1995;95;50.