Occasionally your baby's poop will have identifiable chunks of food in it or be tinged with a surprising hue of the rainbow, like red, orange, or dark blue. Red could mean beets, orange suggests carrots, and dark blue implies blueberries (you may see pieces of blueberry skin in there, too).
Not to worry! You're probably seeing this because certain foods are only partially digestible or travel so quickly through the intestines that they don't have time to completely break down. It also happens when your baby eats a lot of one type of food or doesn't chew a mouthful completely before he swallows.
The time to call the doctor is if your baby's poop consistently has undigested food in it. The doctor will check to make sure your baby's intestines are absorbing food and nutrients properly.
In babies, diarrhea is very runny and appears to be made up of water more than solids. It can be yellow, green, or brown and can seep or "explode" out of the diaper.
Diarrhea can be a sign of an infection or allergy, and if it lasts for a while without being treated, can lead to dehydration. Call the doctor if your baby is 3 months old or younger, has more than two or three diarrhea-filled diapers, or continues having diarrhea for more than a day or two.
It's also wise to call the doctor if your baby's diarrhea contains visible blood or mucus.
Constipation
If your baby's poop is hard and looks like little pebbles, she's probably constipated. Your baby may be visibly uncomfortable when she's pooping, and the poop may even be tinged with blood from irritating the anus on the way out.
One or two pebbly diapers isn't a concern, but if your baby has three or more (or if you see blood), it's best to call the doctor. Constipation often happens in babies who are being introduced to solid foods, or it can be a sign of milk or soy protein sensitivity or a lack of tolerance to something in breast milk or formula. Your doctor may recommend giving your baby water, pear juice, or prune juice to help move things along.
Poop with mucus
Does your baby's diaper look like it's been slimed? Greenish poop streaked with shiny, glistening strings means there's mucus in it. This sometimes happens when a baby is especially drooly, since mucus in saliva often goes undigested.
But mucus in poop is also a telltale sign of an infection or allergy. If it's accompanied by any other symptoms or shows up in your baby's diaper for two days or more, call the doctor to rule out any problems.
Bloody poop
Sometimes the blood in a baby's poop is bright red, and sometimes it's black (which means it's been digested).
Bright red blood can show up in baby poop for a few different reasons. Call your doctor if you notice:
*Normal poop tinged with red blood, which is often a sign of a milk protein allergy (pictured above).
*Constipated poop with a hint of red blood, likely a result of tears in the anus or tiny hemorrhoids.
*Diarrhea mixed with red blood, which can indicate a bacterial infection.
When black blood appears in a baby's diaper – usually in little flecks that look like black poppy or sesame seeds – it's often because the baby is breastfed and swallowing blood from Mom's cracked and bleeding nipples. While this is a sign that you need some pain relief, it doesn't pose a threat to your baby. Still, you should call the doctor to make sure it's not something more serious, like bleeding from your baby's intestines.