Digestive

Baby Foamy or Frothy Poop

Editorially reviewed | Sources: AAP, AAP, CDC|Updated June 2026

The short answer

Foamy or frothy poop in babies is usually caused by excess gas in the stool and is most commonly seen in breastfed babies who may be getting more foremilk (the thinner, lactose-rich milk at the beginning of a feed) relative to hindmilk. It can also occur with a mild stomach bug or a food sensitivity. In most cases, it is not a serious concern and resolves with simple feeding adjustments.

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By Age

What to expect by age

0-3 months

Foamy, frothy poop in young breastfed babies is most often related to a foremilk-hindmilk imbalance. If your baby is not draining the breast fully before switching sides, they may get more lactose-rich foremilk, which can ferment in the gut and produce gas and frothy stools. Try allowing your baby to finish one breast before offering the other. Foamy stools can also appear green.

3-6 months

Foamy stools may continue if the foremilk-hindmilk balance issue persists, but many babies outgrow this as feeding patterns regulate. If foamy stools are accompanied by significant gas, fussiness during or after feeds, and slow weight gain, consulting a lactation specialist can be very helpful. In formula-fed babies, foamy stools can sometimes indicate a sensitivity to the formula.

6-12 months

As babies start solid foods, foamy stools become less common. If they do occur, they may be related to a specific food that causes gas or mild digestive upset. A stomach bug can also produce foamy, loose stools temporarily. If foamy stools are a new development that persists, mention it at your next pediatrician visit.

12-36 months

Foamy stools in toddlers are less common and most often related to a viral illness causing temporary diarrhea. Lactose intolerance, though uncommon in children under 3, can cause foamy, gassy stools after consuming dairy. If your toddler has persistent foamy stools, especially with other digestive symptoms, discuss it with your pediatrician.

What Should You Do?

When to take action

Probably normal when...
  • Your breastfed baby has occasional frothy stools but is feeding well and gaining weight normally
  • Foamy stools appear during a mild cold or stomach bug and resolve within a few days
  • Your baby has some frothy stools along with normal-looking stools
  • Foamy stools improve when you adjust breastfeeding technique to let your baby fully drain one breast before switching
Mention at your next visit when...
  • Your breastfed baby consistently has foamy green stools and seems fussy or uncomfortable during feeds
  • Foamy stools are accompanied by poor weight gain or slow growth
  • Your baby has foamy, mucusy stools that persist for more than a week
  • You suspect a food allergy or intolerance may be causing the foamy stools
Act now when...
  • Foamy, watery stools are very frequent and your baby shows signs of dehydration such as fewer wet diapers, no tears, dry mouth, or lethargy
  • Foamy stools contain blood or significant mucus along with fever or vomiting

Sources

Trust your instincts. If something feels wrong, reach out to your pediatrician.

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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.

Tummy Massage for Baby Gas

Gentle abdominal massage can help relieve gas and discomfort in babies by encouraging gas to move through the intestines. The technique involves gentle clockwise circular motions on the belly (following the direction of the digestive tract), the "I Love U" stroke pattern, and gentle knee-to-tummy movements. Massage also provides comforting touch that can soothe a fussy baby.

Silent Reflux in Baby

Silent reflux occurs when stomach acid rises into the esophagus and throat but is swallowed back down rather than spit up. Babies with silent reflux may be fussy during or after feeds, arch their back, have hoarse crying, or refuse to eat, but without visible spitting up. It can be harder to diagnose than typical reflux because there is no obvious spit-up.

Bicycle Legs Technique for Gas

Bicycle legs is a simple, effective technique for helping babies pass trapped gas. Gently moving your baby's legs in a cycling motion pushes against the abdomen and helps gas move through the intestines. Combined with gentle belly massage and tummy time, it is one of the best non-medical approaches to gas relief in infants.

Dark Blood in Baby's Stool

Dark or black blood in stool (melena) is different from bright red blood and may indicate bleeding from the upper digestive tract (stomach or upper intestine). In newborns, black stools in the first few days (meconium) are normal. Beyond the first week, dark, tarry, or coffee-ground-like material in stool needs prompt medical evaluation. Some dark-colored foods and iron supplements can also darken stools without being blood.