Science of baby sleep
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Baby colic: How your newborn baby’s gut impacts their health

Medically Reviewed Dr. Leslie Treece, MD, FAAP, a board-certified pediatrician
Written by Cradlewise Staff
If your baby cries for hours every evening and nothing you try seems to help; it is one of the hardest parts of early parenthood. It’s called baby colic, and it affects a large number of babies in their first few months.
The rule of three sums it up: crying for more than 3 hours a day, on more than 3 days a week, for more than 3 weeks. The good news is that colic isn’t a sign that something is wrong with your baby, and it always resolves on its own.
We spoke with Dr. Leslie Treece, MD, FAAP, a board-certified pediatrician, and Mindy Cockeram, Board Certified Lactation Consultant, Author, and Founder of learn4birth, to understand what’s actually happening inside your baby’s gut, what genuinely helps, and when it’s worth a call to your pediatrician.
What is colic in babies?
Babies cry, it’s how they communicate needs and feelings they don’t have words for yet. Colic is different. It’s prolonged, intense crying that doesn’t have an obvious cause, and it follows a recognizable pattern known as the rule of three:
- Crying for more than 3 hours a day
- On more than 3 days a week
- For more than 3 weeks in a row
If that sounds like your baby, know that colic affects a significant share of babies in their first few months.
Did you know?
Colic was first formally described by pediatric researchers back in 1954, and while treatments have come a long way, the core mystery, exactly why it happens, is still unknown and being studied today.
When does colic start?
Colic tends to begin around 2 to 4 weeks of age, once your baby’s early newborn haze has worn off just enough for the crying spells to stand out. It typically peaks around 6 weeks.
How long does colic last?
Most colic resolves on its own between 3 and 4 months, though some cases stretch closer to 5 to 6 months. There’s no way to speed this up completely, but the soothing techniques below can make individual episodes more manageable while you wait for it to phase out.
Can colic start late?
Occasionally, yes. Some babies don’t show colic-like crying until 6 to 8 weeks. It’s less common, but not a cause for alarm, the same rule-of-three pattern and general timeline still apply, just that it shifts to a later period.
Does colic show up differently in premature babies?
Dr. Treece adds that premature babies can also have more issues with other underlying conditions, so it’s worth keeping a slightly lower threshold for checking in with your pediatrician rather than assuming it’s colic by default.
How can I tell if my baby has colic
Beyond the crying itself, colic tends to show up alongside a specific cluster of signs:
- Excessive crying that happens at a predictable time, often late afternoon or evening
- Crying and fussiness that is unrelated to fever, hunger, or the need for a diaper change
- A flushed face, clenched fists, or an arched back
- Legs pulled up toward the belly, or stiffened and straightened
- Passing gas, often audibly, during or after a crying spell
- A baby who otherwise feeds and behaves normally between episodes
Can a baby have colic without crying constantly?
Yes. Some babies show colic more through fussiness, gas, and visible discomfort than nonstop screaming. The rule-of-three pattern, duration, frequency, and weeks, still applies even if the crying itself is less intense than the classic image of colic.
Colic vs. reflux
| Feature | Colic | Reflux |
|---|---|---|
| Crying pattern | Predictable, often evening; resolves by ~4 months | Can happen throughout the day, especially after feeds |
| Spitting up | Not typically present | Frequent spit-up or vomiting |
| Feeding behavior | Usually feeds normally between episodes | May refuse feeds or arch away during feeding |
If your baby is spitting up frequently, refusing feeds, or seems to be in pain specifically around feeding times, it could be reflux. Its management is different from colic.
What causes colic in babies?
Mindy Cockeram, a board-certified lactation consultant, lists a few probable theories for colic in babies:
- Baby’s struggle to digest the protein casein from your breastmilk.
- The manner in which antibiotics may have affected your baby’s immature gut lining.
- Not feeding equal amounts on both breasts exposes your baby to foremilk overload with not enough fat.
Researchers have also connected colic to several overlapping factors beyond what Dr. Treece and Mindy describe:
- Feeding patterns, including overfeeding, underfeeding, or infrequent burping.
- Possible sensitivities, including to cow’s milk protein.
- Differences in gut bacteria, including lower levels of protective strains like Bifidobacterium and Lactobacillus.
- Family stress and parental anxiety though it’s unclear whether stress contributes to colic or results from it.
Why is colic worse at night?
Dr. Treece says it could be related to altered day/night rhythm, fatigue, or possibly sensory overload leading to deterioration in colic stretches at night, while Mindy Cockeram attributes these colic episodes to low milk supply in breastfeeding mothers in the late afternoon leading to babies being more fussy due to hunger in the evening and night.
Colic in breastfed vs. formula-fed babies
Colic affects babies regardless of how they’re fed, but the contributing factors can differ slightly. In breastfed babies, a parent’s diet or a shallow latch may play a small role for some infants. In formula-fed babies, how the formula’s proteins are broken down can matter more.
Dr. Leslie Treece doesn’t believe that a breastfeeding position can cause colic specifically, but certainly the position and the latch can cause gas and belly pain. It might be interpreted as colic by some.
And Mindy Cockeram says, “Babies with severe tongue ties may be more prone to colic.”
What can pass into breast milk and occasionally cause discomfort are intact proteins, most commonly from cow’s milk.
How to soothe a colicky baby
While there’s no single remedy for colic, a combination of these approaches tends to help take the edge off.
- Motion and holding
Gentle, rhythmic motion, rocking, swaying, or a car ride, can help calm a crying baby. Holding your baby upright against your chest, or trying a football hold across your forearm, can also ease pressure on their belly.
- Sound and white noise
Consistent, low white noise can help mimic the sounds of the womb and soothe an overstimulated nervous system. This is part of why gentle motion and sound are often paired together during fussy stretches.
- Feeding adjustments
Smaller, more frequent feeds and thorough burping between sides can help reduce swallowed air. If bottle-feeding, paced feeding and anti-colic bottle nipples may also help.
- Tummy massage and movement
Try these:
- Gentle abdominal massage can help move trapped gas along.
- Lay your baby on their back and use light, circular motions with your fingertips around their belly button.
- Try the bicycle-legs technique: hold their ankles and gently pedal their legs in a cycling motion.
- Supervised tummy time can also help once your baby is a little steadier.
- Rock your baby and walk them in a baby carrier.
Cradlewise Note: As far as using the Windi is concerned, it is advisable to talk with your pediatrician before using it.
What the research says about gut health
Babies with colic tend to have lower levels of protective gut bacteria like Bifidobacterium and Lactobacillus, and higher levels of gas-producing bacteria like E. coli. This is part of why gut-focused approaches have gained attention as a genuine, evidence-backed angle on colic.
You may run a gut microbiome test using your baby’s stool sample. The test does not provide a diagnosis, but provides parents with research-based health associations.
Cradlewise note: L. reuteri appears to work best in exclusively breastfed babies specifically, and the evidence, while promising, is still described as weak by pediatric researchers. Talk to your pediatrician in case you opt for the gut microbiome test and surely before offering any supplement to your baby.
Gut health and sleep
In addition to a link between baby gut health and colic, there is a dynamic relationship between gut health and baby sleep as well.
According to a 2022 study in Progress in Neurobiology, baby gut health can impact a baby’s sleep as early as three months old. This study reveals that infants with abundant Bifidobacterium show less slow-wave, delta-wave activity often interpreted as signs of “light sleep.” In short, high levels of Bifidobacterium may help protect your baby against colic and light sleep.
How colic affects parents too
Colic affects the parents as well: The sleep deprivation, helplessness, and hours of crying can take a real toll on parents. It’s normal to feel exhausted, anxious, or even guilty during this period, even though it’s not your fault.
Cradlewise Tip: Trade off soothing shifts with a partner or support person where you can, even in short intervals. Stepping away for even ten minutes to breathe lets you come back with a better frame of mind.
When to call your doctor
Most colic is uncomfortable but harmless.
Call your pediatrician if you notice:
- consistent discomfort
- fever
- vomiting
- diarrhea
- blood or mucus in the stool
- poor weight gain
- your baby is unusually lethargic or difficult to rouse
Conclusion
Baby colic is exhausting, but it’s temporary. Your baby’s gut and nervous system are developing and still learning how to work together. This phase passes as they mature.
Lean on the people around you, try what feels manageable, and know that calmer evenings are coming.
FAQs
Q: How to tell the difference between crying and colic?
A: Regular crying usually has an identifiable cause, hunger, a wet diaper, tiredness, and settles once that need is met. Colic follows the rule of three: over 3 hours a day, over 3 days a week, for over 3 weeks, often at a predictable time of day, without an obvious trigger.
Q: Can a baby have colic without crying constantly?
A: Yes. Some babies show colic more through fussiness and discomfort than nonstop screaming, though the same duration and frequency pattern still applies.
Q: How long do babies cry if they have colic?
A: By definition, colic involves crying for more than 3 hours a day. Individual episodes often cluster in the evening and can last anywhere from a few minutes to a couple of hours at a stretch.
Q: What does a colic cry sound like?
A: Colic crying tends to be more intense and harder to soothe than typical fussiness, often high-pitched, and paired with a flushed face, clenched fists, or an arched back.
Q: Why is colic worse at night?
A: The evening pattern is thought to relate to an altered day-night rhythm, accumulated fatigue, or sensory overload after a full day, though the exact biological reason isn’t fully understood.
Q: How to tell if baby is colic or gassy?
A: Gas alone usually resolves with burping, positioning changes, or passing gas, and doesn’t follow colic’s specific 3-hours/3-days/3-weeks pattern. Persistent gas can be one contributor to colic, but colic itself is defined by the broader crying pattern, not gas alone.
Q: Can breastfeeding position or the way the baby latches cause colic?
A: Not colic specifically, but a shallow latch or feeding position can contribute to gas and belly pain that may be interpreted as colic. Working with a lactation consultant on latch can help rule this out.
You may also like:
- Why is my baby grunting in sleep? What’s normal and when to worry.
- Safe sleep for babies: The do’s and don’ts for new parents.
- What are the 3 types of breast milk? A guide for curious parents.
Sources:
- Colic was first formally described by pediatric researchers back in 1954. Stat Pearls. 2023. Infantile Colic.
- Colic peaks around 6 weeks. AAP. 2024. Colic Relief Tips for Parents.
- Sensitivity to cow’s milk protein. Allergol Select. 2022. Non-IgE mediated food allergies in breastfed children: A clinical challenge.
- Family stress can cause colic. Stat Pearls. 2023. Infantile Colic.
- Gut health and sleep. Progress in Neurobiology. 2022. From Alpha Diversity to Zzz: Interactions among sleep, the brain, and gut microbiota in the first year of life.


