Baby Diarrhea
The short answer
Baby diarrhea is defined as a sudden increase in the frequency and wateriness of stools compared to your baby's normal pattern. Breastfed babies naturally have loose, seedy stools, which is not diarrhea. True diarrhea in babies is most often caused by a viral infection and usually resolves on its own, but preventing dehydration is the most important thing you can do.
By Age
What to expect by age
Breastfed babies often have very loose, yellow, seedy stools multiple times per day, which is completely normal. Diarrhea in this age group means stools are significantly more watery and frequent than your baby's baseline. In young infants, diarrhea can lead to dehydration more quickly, so monitoring wet diapers closely is essential.
As babies start solid foods, their stool consistency normally changes and becomes more formed. Diarrhea at this age is often caused by viral gastroenteritis or a reaction to a new food. Continue breastfeeding or formula feeding as usual during diarrhea episodes, and offer small amounts of water if your baby is over 6 months.
Toddler diarrhea, also called functional diarrhea, is a common condition where toddlers have multiple loose stools per day but are otherwise healthy and growing well. It is often related to excessive juice or fluid intake. True infectious diarrhea at this age is usually caused by rotavirus or norovirus and typically resolves within 5 to 7 days.
Persistent or chronic diarrhea in this age group may warrant investigation for food intolerances, celiac disease, or other digestive conditions. However, most episodes of diarrhea in toddlers are acute and viral. Keeping your child hydrated with an oral rehydration solution and a normal diet is the recommended approach.
What Should You Do?
When to take action
- Your breastfed baby has frequent loose, seedy stools but is feeding well and gaining weight
- Your baby has a few loose stools after trying a new food but is otherwise happy and well
- Your toddler has loose stools but is active, eating, drinking, and growing normally
- Your baby has slightly looser stools during teething but no other signs of illness
- Diarrhea lasts more than a few days without improvement
- Your baby has diarrhea along with a low-grade fever but is still drinking fluids
- You notice undigested food consistently appearing in watery stools
- Your baby has recurrent episodes of diarrhea that seem related to a specific food
- Your baby shows signs of dehydration: fewer than 6 wet diapers in 24 hours, no tears when crying, dry mouth, sunken fontanelle, or unusual drowsiness
- There is blood or mucus in the diarrhea, or stools are black and tarry
- Your baby under 3 months has diarrhea with fever above 100.4 degrees Fahrenheit (38 degrees Celsius)
Sources
Related Resources
Related Digestive Concerns
My Baby's Belly Looks Swollen
A rounded, slightly protruding belly is completely normal in babies and toddlers due to immature abdominal muscles and their proportionally larger organs. However, if the belly becomes suddenly swollen, feels hard and tight, or is accompanied by pain, vomiting, or changes in bowel movements, it needs medical evaluation as it could signal gas buildup, constipation, or rarely, something more serious.
My Baby Has an Anal Fissure (Blood When Pooping)
A small streak of bright red blood on the surface of your baby's stool or on the diaper is most commonly caused by an anal fissure, which is a tiny tear in the skin around the anus from passing hard stool. Anal fissures are very common in babies and toddlers and usually heal on their own with simple measures like keeping stools soft. While this is rarely serious, any blood in your baby's stool should be mentioned to your pediatrician.
My Baby Eats Non-Food Items (Pica)
It is completely normal for babies and young toddlers to explore by putting objects in their mouths. True pica, which is the persistent eating of non-food substances, is uncommon before age two and may be linked to iron deficiency or developmental factors. If your child repeatedly seeks out and eats non-food items past the typical mouthing stage, it is worth discussing with your pediatrician.
Baby Excessive Gas After Starting Solids
Increased gas after starting solid foods is completely normal and expected. Your baby's digestive system is encountering new proteins, fibers, and sugars for the first time and needs time to adapt. The gut bacteria are also diversifying, which naturally produces more gas. This typically improves within a few weeks as the digestive system adjusts to each new food.
My Baby Gulps Air While Feeding
Swallowing some air during feeding is normal for all babies, but excessive air gulping can lead to gas, hiccups, and spit-up. Common causes include fast milk flow, poor latch (if breastfeeding), bottle nipple flow that's too fast or slow, and crying before feeds. Simple adjustments to feeding position, pacing, and equipment can usually help reduce air intake significantly.
Baby Poop Color Changes with Solids
Dramatic changes in poop color after starting solids are completely normal and expected. What your baby eats directly affects stool color - carrots may turn poop orange, spinach makes it green, beets can make it reddish, and blueberries can turn it dark blue-black. As long as your baby is comfortable and the stool is not white, black (tarry), or bright red with blood, these color changes are harmless.