Colic in Babies: A Pediatrician's Guide to Soothing and When to Worry

If you're searching for help with a colic baby, you're not alone. Colic is a pattern of intense, hard-to-soothe crying in an otherwise healthy baby. It usually starts around 2 weeks of age, peaks around 6 weeks, and fades by 3 to 4 months. About 1 in 5 babies has colic, and it isn't caused by anything you did wrong. If your baby is feeding well, gaining weight, and otherwise healthy but cries for hours at a time, often peaking in the late afternoon or evening, you're likely looking at colic. This guide walks through what colic is, how to soothe a colicky baby safely, and when crying might be something else. We'll also cover the red flags that mean it's time to call your pediatrician.

In Blueberry Pediatrics telehealth visits with thousands of families, the most common pattern parents describe is intense, inconsolable crying that begins in the late afternoon and peaks around 6 weeks of age. Babies feed, gain weight, and look healthy between cries, but the evening hours are exhausting for the whole household.

Key Takeaways

• Colic is long, hard-to-soothe crying in a healthy baby, usually 3 or more hours a day, often peaking in the late afternoon.
• It typically starts around 2 weeks, peaks at 6 weeks, and improves by 3 to 4 months.
• Colic is a diagnosis of exclusion. A baby who is feeding, growing, and otherwise well most likely has colic.
• The 5 S's, swaddling (stop at the first sign of rolling, usually 2 to 4 months), side or stomach hold while awake, shushing, swinging, and sucking, are the most-studied set of in-the-moment soothing techniques.
• For breastfed babies, the probiotic Lactobacillus reuteri DSM 17938 may reduce daily crying time. The same evidence does not apply to formula-fed babies.
• It is never okay to shake a baby. If you feel overwhelmed, place your baby on their back in a safe place and step away for 5 to 10 minutes.
• Fever in a baby under 3 months, forceful or green vomiting, blood in the stool, poor feeding, or lethargy are red flags. Call your pediatrician right away.

What Is Colic?

Colic is the medical term for a pattern of long, intense crying in a baby who is otherwise healthy. The crying is hard to soothe, tends to follow a daily rhythm (often peaking in the late afternoon or evening), and resolves on its own as the baby gets older. About 1 in 5 babies has colic, according to the American Academy of Pediatrics.

The most important thing to understand about colic is that it is a diagnosis of exclusion. That means a pediatrician calls a baby "colicky" only after confirming the baby is feeding well, gaining weight, has no fever, and isn't sick. If something else is wrong, the diagnosis is not colic, and that's exactly when you want a pediatrician's help.

The Rule of 3s

Pediatricians have used a shorthand called the "rule of 3s" since 1954: crying more than 3 hours a day, more than 3 days a week, for more than 3 weeks, in an otherwise healthy baby. It came from a study by Dr. Morris Wessel and is still widely taught. In modern practice, though, your pediatrician can usually recognize colic before 3 weeks have passed once the pattern is clear. You do not have to wait three weeks of crying to ask for help.

How to Tell If Your Baby Has Colic

Colic symptoms have a recognizable shape, and the colic newborn pattern is usually clear once you know what to look for. The features below tend to cluster together:

• Crying that goes on for long stretches (often an hour or more at a time, sometimes 3+ hours a day).
• Crying that is hard or impossible to soothe with feeding, holding, or rocking.
• A daily pattern, with the worst stretch often falling in the late afternoon or evening.
• A baby who looks like they're in pain (clenched fists, drawn-up legs, arched back, red face), but who is otherwise growing, feeding, and developing normally.
• Crying that begins around 2 weeks of age and tapers off by 3 to 4 months.

If your baby looks unwell between crying spells, isn't feeding, isn't gaining weight, or has a fever, the crying isn't colic. It's a sign to call your pediatrician sooner rather than later.

What Causes Colic?

The honest answer is that we don't know for sure. Decades of research have not pinned down a single cause. The leading theories include:

• An immature digestive system, which can lead to discomfort with feeding and gas.
• Differences in the developing gut microbiome (the trillions of bacteria that live in a baby's intestines).
• A still-developing nervous system that is more easily overwhelmed by stimulation.
• Normal variation in newborn temperament and how babies regulate crying.

What we can say: colic is not caused by bad parenting, by something you ate (if you're breastfeeding), or by holding your baby too much. Colicky babies are healthy babies, and this is a phase they pass through.

How to Soothe a Colicky Baby

There is no single fix for colic, but there are evidence-based ways to calm a crying baby in the moment. The most-studied set of in-the-moment soothing techniques is called the 5 S's, developed by pediatrician Dr. Harvey Karp. A randomized clinical trial in Pediatrics (Harrington and colleagues, 2012) found the 5 S's reduced crying after routine infant immunizations more than standard parental comforting. It is the strongest evidence we have that these techniques soothe babies in the moment, and the same calming techniques are widely used for colicky babies.

The 5 S's

1. Swaddle. Wrap your baby snugly in a thin blanket, with arms in. Keep the swaddle loose around the hips so the legs can bend (this helps prevent hip problems). Stop swaddling at the first sign of rolling, usually around 2 to 4 months.
2. Side or stomach hold. Hold your baby on their side or stomach in your arms while awake. This position can calm a fussy baby. Important: babies should always be placed on their BACK to sleep. Side or stomach is for soothing while you're holding them, never for sleep.
3. Shush. Make a steady, loud "shhhhh" sound near your baby's ear, or use a white-noise machine at a moderate volume. The sound mimics what babies heard in the womb.
4. Swing. Hold your baby securely and use small, fast, jiggly motions (think "tiny shivers," not big rocking). A motorized swing or a walk in a baby carrier can help, too.
5. Suck. Offer a pacifier, a clean finger, or a breast. Sucking activates a built-in calming reflex.

Other things that often help: walking outside, a warm bath, skin-to-skin contact, or rhythmic motion (a stroller walk, car ride, or carrier). Try one, give it a few minutes, and move to the next if it isn't working.

A Safety Note: It Is Never Okay to Shake a Baby

Colic is one of the hardest things parents go through. Hours of crying that you can't fix is exhausting and emotionally draining. It is also one of the strongest known triggers for shaken baby syndrome, which can cause permanent brain injury or death.

If you feel overwhelmed:

• Place your baby on their back in a safe spot (a crib or bassinet with no loose blankets, pillows, or toys).
• Close the door and step away for 5 to 10 minutes.
• Call a partner, family member, or friend to take over.
• If you are struggling emotionally, call your pediatrician or your own doctor. Postpartum depression and anxiety are common and very treatable.

Walking away from a crying baby for a few minutes does not make you a bad parent. It is one of the most important things you can do to keep your baby safe.

What May Help: Probiotics, Gas Drops, and Lactase Drops

Parents ask about these often, so here's what the research shows.

• Gas drops (simethicone): Safe to use, but clinical trials show they don't reduce colic crying any more than a placebo. They aren't likely to harm your baby, but they probably won't help either.
• Probiotics: For breastfed babies, one specific probiotic, the L. reuteri strain DSM 17938 (a specific bacterial strain studied for infant colic), may help reduce daily crying time. The same studies did not find a benefit for formula-fed babies. Talk to your pediatrician before starting any probiotic, especially if your baby was born premature or has a medical condition.
• Lactase drops: Sometimes suggested, but the research is mixed and they aren't a first-line option.

What to Skip: Gripe Water, Honey, and Chiropractic

• Gripe water: Not regulated by the FDA, formulations vary widely, and pediatricians generally don't recommend it.
• Honey: Never give honey to a baby under 12 months. It carries a risk of infant botulism. (This isn't specific to colic, but it's worth repeating because some traditional remedies include it.)
• Chiropractic or craniosacral therapy: Studies do not show a consistent benefit for colic. Not recommended.

When Colic Is Actually Something Else

Most inconsolable crying in a healthy baby is colic, but a small number of conditions can look just like it; here's how pediatricians tell them apart. Because colic is a diagnosis of exclusion, it's worth knowing the two most common conditions parents and pediatricians rule out: gastroesophageal reflux disease (GERD) and cow's milk protein allergy (CMPA). Both have features that overlap with colic, especially in the first few months, but each comes with its own pattern of symptoms that helps your pediatrician sort them out. The comparison below covers GERD, CMPA, and a short list of less common but important causes of inconsolable crying, so you know what your pediatrician will think about, and what's worth a call.

Colic vs. Reflux (GERD)

Knowing the signs of colic vs reflux starts with one fact: most babies spit up, and that alone is not reflux disease. Pediatricians call it GERD only when spitting up comes with problems like poor weight gain, refusing feeds, distress during feeds (back-arching, pulling away), or persistent irritability tied to feeding. Colic crying tends to be late-day and not tied to feeds. Reflux-related crying tends to happen during or after feeds and often eases when the baby is upright.

Colic vs. Cow's Milk Protein Allergy (CMPA)

Cow's milk protein allergy is uncommon, affecting about 2 to 3 percent of infants. Unlike colic, CMPA usually comes with one or more of these signs: streaks of blood or mucus in the stool, eczema (especially severe or early-onset), forceful or frequent vomiting, poor weight gain, or a strong family history of asthma, eczema, or food allergies. If those features are present, talk to your pediatrician. A 2 to 4 week trial of an extensively hydrolyzed formula (for formula-fed babies) or a maternal dairy-free diet (for breastfeeding moms) is the usual first step.

Other Conditions to Rule Out

A few less common but important causes pediatricians rule out:

• Hair tourniquet: A loose hair wrapped tightly around a finger, toe, or genital that cuts off circulation. Easy to miss and easy to fix once found.
• Corneal abrasion: A small scratch on the eye that causes severe pain.
• Urinary tract infection: More common in young babies than parents realize, and often presents only as crying and poor feeding.
• Incarcerated hernia: A swollen, tender bulge in the groin or scrotum is a surgical emergency.
• Intussusception: A bowel telescoping problem that causes sudden, severe crying in episodes, sometimes with red "currant jelly" stools.

A sudden change in your baby's cry, either a new pattern in a previously colicky baby or sudden intense crying in a baby who was content, is a red flag and worth a same-day call to your pediatrician.

Quick Comparison Snapshot

• Feeding, growing, and otherwise well, with late-day crying peaks: think colic. Use soothing strategies.
• Crying tied to feeds, back-arching, frequent forceful spit-up: think reflux. Try upright positioning and call your pediatrician.
• Blood or mucus in the stool, eczema, or strong family allergy history: think CMPA. Call your pediatrician about a trial.
• Fever, poor weight gain, lethargy, or a baby who looks unwell: it isn't colic. Call your pediatrician right away.

When to Call Your Pediatrician

If your baby has a fever, isn't feeding, or seems suddenly different from their usual self, call your pediatrician right away or seek emergency care.

Call your pediatrician (or seek emergency care) if your baby has any of these red flags:

• Fever. In a baby under 3 months, a rectal temperature of 100.4°F (38°C) or higher is a medical emergency, almost always evaluated in an emergency room.
• Forceful (projectile) vomiting, vomit that is green or yellow (bilious), or vomit with blood in it.
• Blood, mucus, or unusual color in the stool (black, bloody, or white/clay-colored stools).
• Refusing feeds for more than a few hours, or feeding much less than usual.
• Poor weight gain or weight loss at well-baby visits.
• Lethargy, floppiness, or a baby who is hard to wake.
• High-pitched, weak, or persistent crying that's different from the usual pattern.
• A swollen or tender belly, or crying when the belly is pressed.
• Trouble breathing (fast breathing, grunting, flaring nostrils, or pulling between the ribs).
• A swollen, tender bulge in the groin or scrotum (possible hernia, urgent).
• A sudden change in crying pattern from a previously content baby (think hair tourniquet, eye scratch, or other acute cause).
• Any time you feel something is wrong. Trust your gut.

How Long Does Colic Last?

When does colic stop for most babies? Colic typically peaks around 6 weeks of age and significantly improves by 3 to 4 months. A small number of babies still have colicky episodes up to 5 or 6 months, but persistent inconsolable crying past 5 months should prompt a pediatrician visit to look for other causes.

Here's the encouraging part: colic ends. Studies have followed colicky babies into childhood, and there is no link between colic and later behavioral, sleep, or developmental problems. The crying is real, the exhaustion is real, but it is a phase, not a forecast.

The Period of PURPLE Crying

Researchers have given normal infant crying a more parent-friendly name: the Period of PURPLE Crying. It's a way of describing what's normal for a baby's crying between about 2 weeks and 3 to 4 months, and it gives parents a vocabulary for what they're experiencing. The acronym stands for:

• Peak of crying (around 2 months of age).
• Unexpected (the crying comes and goes for no apparent reason).
• Resists soothing (sometimes nothing you do helps in the moment).
• Pain-like face (babies can look like they're in pain when they're not).
• Long-lasting (episodes can last 30 to 40 minutes or more).
• Evening (often worst in the late afternoon and evening).

Endorsed by the American Academy of Pediatrics and included in most US newborn discharge education, the program's main message is simple: this is normal, it will pass, and it is never okay to shake a baby.

How a Virtual Pediatrician Can Help

Colic doesn't require lab tests to diagnose. Pediatricians make the call based on history, feeding and growth patterns, and observation, which makes it well suited to a virtual visit. A pediatrician can listen to your baby's cry, watch a feed, review the growth curve, and rule out reflux or milk protein allergy, usually faster than it takes to get to the office.

Blueberry Pediatrics gives you 24/7 access to board-certified pediatricians by video, phone, or message, for one flat monthly price and no per-visit fees. If you're up at 2 a.m. with a crying baby, you can talk to a pediatrician within minutes.

Join Blueberry Pediatrics and get the support you need through the colic months.

Frequently Asked Questions

What is colic in a baby?

Colic is a pattern of intense, inconsolable crying in an otherwise healthy baby. It usually starts around 2 weeks of age, peaks around 6 weeks, and improves significantly by 3 to 4 months. About 1 in 5 babies has colic. The cause isn't fully understood, but it isn't anything you did wrong.

How do I know if my baby has colic?

Colic crying tends to follow a pattern: it lasts a long time (often hours), is hard or impossible to soothe, often peaks in the late afternoon or evening, and happens in a baby who is otherwise feeding well, gaining weight, and healthy. Pediatricians sometimes use the "rule of 3s," crying more than 3 hours a day, more than 3 days a week, for more than 3 weeks.

What causes colic in babies?

The exact cause of colic isn't known. Theories include an immature digestive system, differences in the developing gut microbiome, sensitivity to stimulation, and a newborn's still-developing nervous system. What we do know: colic isn't caused by bad parenting, by anything the parents ate or did, or by being "spoiled" by being held.

How long does colic last?

Most babies' colic peaks around 6 weeks of age and improves significantly by 3 to 4 months. A small percentage of babies still have some colicky episodes up to 5 or 6 months. If excessive crying continues past 5 months, it's worth a pediatrician visit to rule out other causes.

What is the rule of 3s for colic?

The rule of 3s is a guideline pediatricians have used since 1954 to describe colic: crying that lasts more than 3 hours a day, more than 3 days a week, for more than 3 weeks, in a healthy baby. In modern practice, your pediatrician can often recognize colic before 3 weeks of crying when the pattern is clear, so you don't have to wait 3 weeks to get help.

How can I soothe a colicky baby?

Evidence-based soothing techniques include the 5 S's: swaddling (stop at the first sign of rolling, usually 2 to 4 months), holding the baby on their side or stomach (in your arms, while awake), shushing or white noise, swinging or rocking, and giving a pacifier to suck. Other things that may help: walking with the baby in a carrier, going outside for a change of scenery, and a warm bath. Babies should always be placed on their BACK to sleep.

Is colic the same as gas or reflux?

No. Colic, gas, and reflux are different. Colic is a pattern of inconsolable crying in an otherwise healthy baby. Gas is uncomfortable but normal and brief. Reflux (GER) is spitting up. It's only "GERD" if the baby is also unhappy, not gaining weight, or having feeding problems. A baby can have colic and reflux at the same time, but they need different approaches.

Should I switch formula if my baby has colic?

Usually not. Most babies with colic don't have a milk protein allergy, and switching formulas without a reason can be expensive and add stress. If your pediatrician suspects a cow's milk protein allergy, usually because of other signs like blood in the stool, eczema, or vomiting, they may recommend a short trial of a hydrolyzed formula. Don't change formulas on your own.

When should I worry about colic?

Call your pediatrician right away if your baby has a fever (100.4°F or higher rectally if under 3 months), is vomiting forcefully or vomiting blood or green/yellow fluid, has blood in the stool, is not feeding well, isn't gaining weight, is hard to wake or unusually limp, is having trouble breathing, or has crying that's suddenly different from the usual pattern. Also call if you, the parent, feel something is wrong. You know your baby best.

Can a virtual pediatrician diagnose colic?

Yes. Colic is diagnosed by history and observation, not by lab tests. A virtual pediatric visit lets a pediatrician hear your baby's cry, see the feeding pattern, and review weight and growth, usually in less time than it takes to drive to the office. Blueberry pediatricians can also help rule out reflux, milk protein allergy, or other causes of fussiness.

Do probiotics help colic?

For breastfed babies, the probiotic Lactobacillus reuteri (strain DSM 17938) may help reduce daily crying time. The same studies did not find a benefit for formula-fed babies. If you're thinking of trying a probiotic, talk to your pediatrician first.

Are gripe water or gas drops safe for colic?

Gas drops (simethicone) are safe, but studies show they don't actually reduce colic crying any more than a placebo. Gripe water isn't regulated by the FDA, formulations vary widely, and pediatricians don't recommend it. The most reliable tools for colic are the 5 S's, time, and (for breastfed babies) possibly L. reuteri probiotics after talking to your pediatrician.

Talk to a Pediatrician Tonight

Colic is one of the hardest stretches of early parenthood. If you have questions or want a pediatrician's eyes on your baby's crying pattern, join Blueberry Pediatrics for 24/7 video, phone, and messaging access to a board-certified pediatrician, for one flat monthly price.

References

American Academy of Pediatrics, HealthyChildren.org. "Colic Relief Tips for Parents." https://www.healthychildren.org/English/ages-stages/baby/crying-colic/Pages/Colic.aspx

Benninga MA, Faure C, Hyman PE, et al. "Childhood Functional Gastrointestinal Disorders: Neonate/Toddler." Gastroenterology. 2016;150(6):1443-1455. https://pubmed.ncbi.nlm.nih.gov/27144632/

Harrington JW, Logan S, Harwell C, et al. "Effective Analgesia Using Physical Interventions for Infant Immunizations." Pediatrics. 2012;129(5):815-822. https://pubmed.ncbi.nlm.nih.gov/22529300/

Sung V, D'Amico F, Cabana MD, et al. "Lactobacillus reuteri to Treat Infant Colic: A Meta-analysis." Pediatrics. 2018;141(1):e20171811. https://pubmed.ncbi.nlm.nih.gov/29279326/

Vandenplas Y, Brough HA, Fiocchi A, et al. "An ESPGHAN Position Paper on the Diagnosis, Management, and Prevention of Cow's Milk Allergy." Journal of Pediatric Gastroenterology and Nutrition. 2024. https://www.espghan.org/dam/jcr:aaf17bec-ca96-403a-8677-eafc202bb35d/J%20pediatr%20gastroenterol%20nutr%20-%202024%20-%20Vandenplas%20-%20An%20ESPGHAN%20Position%20Paper%20on%20the%20Diagnosis%20Management%20and.pdf

Rosen R, Vandenplas Y, Singendonk M, et al. "Pediatric Gastroesophageal Reflux Clinical Practice Guidelines: Joint Recommendations of NASPGHAN and ESPGHAN." Journal of Pediatric Gastroenterology and Nutrition. 2018;66:516-554. https://pmc.ncbi.nlm.nih.gov/articles/PMC5958910/

Roberts DM, Ostapchuk M, O'Brien JG. "Infantile Colic." American Family Physician. 2004;70(4):735-740. https://www.aafp.org/pubs/afp/issues/2004/0815/p735.html

Hjern A, Lindblom K, Reuter A, Silfverdal SA. "A systematic review of prevention and treatment of infantile colic." Acta Paediatrica. 2020. https://pubmed.ncbi.nlm.nih.gov/32202311/

Wessel MA, Cobb JC, Jackson EB, Harris GS, Detwiler AC. "Paroxysmal Fussing in Infancy, Sometimes Called Colic." Pediatrics. 1954;14(5):421-435. https://pubmed.ncbi.nlm.nih.gov/13214956/

National Center on Shaken Baby Syndrome. "Period of PURPLE Crying." https://dontshake.org/purple-crying

StatPearls. "Infantile Colic." Updated 2023. https://www.ncbi.nlm.nih.gov/books/NBK518962/