What Causes Colic in Newborns? Understanding the Triggers

Quick take: Colic in newborns is usually a temporary bout of intense, unexplexplained crying that peaks around 6 weeks and resolves by 4 months. The most common triggers are an immature gut, excess gas, reflux, or a formula intolerance, while parental stress and irregular sleep can make symptoms worse. Most babies outgrow it, but if crying is extreme, accompanied by fever, vomiting, or poor weight gain, see a pediatrician.

It’s 2 a.m., your newborn is wailing nonstop, and you’re scrolling through articles wondering whether the crying is “just colic” or something more serious. You’re not alone—many new parents feel the same mix of exhaustion and worry. The bottom line is that colic follows a recognizable pattern, and while it can be distressing, it’s rarely a sign of a dangerous condition. Below we unpack what causes colic, how feeding and daily routines play a role, and what you can safely try at home. We’ll also tell you when it’s time to call a doctor and give you a handy checklist to track episodes.

In this guide we’ll cover:

• What doctors consider colic and how it’s diagnosed
• The main physiological and environmental triggers
• Feeding‑related factors, including formula and maternal diet
• Practical soothing techniques and daily‑routine tweaks
• Red‑flag signs that need medical attention
• How long colic typically lasts and what to expect as your baby grows

What are the main causes of colic in newborns?

Colic is defined by the “rule of threes”: crying for more than three hours a day, three days a week, for at least three weeks in an otherwise healthy infant. The exact cause remains unknown, but researchers and clinicians have identified several common contributors.

Immature digestive system

Newborns have a gut that is still learning to digest milk. Enzymes are low, and the intestinal lining is more permeable, which can lead to discomfort after feeding. This physiological immaturity is the most widely accepted explanation for why colic peaks between two and six weeks of age.

Excess gas

Air swallowed during feeding (especially with bottle‑feeding) can accumulate in the intestines, causing painful distention. Gas is often blamed because it can be relieved with burping or tummy‑time, yet it rarely explains the full pattern of colic.

Reflux

Gastro‑oesophageal reflux (GER) occurs when stomach contents flow back into the esophagus, irritating the lining and prompting crying. While reflux is common in infants, it can overlap with colic, making it hard to separate the two without a clinical assessment.

Formula intolerance

Some infants react to cow‑milk protein or other components in formula, leading to gastrointestinal upset that mimics colic. Switching to a hypoallergenic or soy‑based formula often reduces symptoms, supporting a link between intolerance and colic.

Environmental and behavioral factors

Parental stress, overstimulation, and irregular sleep patterns can amplify a baby’s crying response. Although these factors don’t cause colic directly, they can lower a newborn’s tolerance to discomfort.

Overall, colic is likely multifactorial—a combination of an immature gut, minor feeding issues, and the surrounding environment.

Recent surveys from the AAP indicate that parents who notice a consistent daily crying pattern are more likely to seek early guidance, which can reduce anxiety and improve outcomes.

How does feeding schedule affect colic in newborns?

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Over‑feeding and large feeds

When a baby takes a large volume in one session, the stomach stretches, which can trigger discomfort and reflux. Splitting feeds into smaller, more frequent sessions often eases this pressure.

Irregular feeding intervals

Skipping a feeding or feeding erratically can cause a hungry infant to become more irritable, potentially escalating into a colic episode. Consistency—feeding every 2‑3 hours for newborns—helps maintain steady blood sugar and reduces fussiness.

Positioning during feed

Upright positioning during and after feeds encourages gravity‑assisted drainage and reduces the chance of air staying in the stomach. A 10‑minute burp after each feeding is a simple, evidence‑based practice recommended by the American Academy of Pediatrics (AAP).

Breastfeeding versus bottle‑feeding

Breastfed babies often experience less gas because the latch can be more efficient, but they can still develop colic. For bottle‑fed infants, using anti‑colic nipples and pacing the flow can cut down swallowed air.

Adjusting the schedule doesn’t cure colic, but it can lessen the severity and frequency of crying spells.

Clinicians often advise parents to keep a simple feeding log for the first month; patterns that emerge can point to specific timing issues that are easily corrected.

Can gas buildup cause colic symptoms in newborns?

Yes, gas can be a contributing factor, but it’s rarely the sole cause. The infant gut produces gas as a by‑product of digestion, and swallowed air adds to the load. When gas accumulates, the abdominal wall stretches, which can trigger a crying response that looks like colic.

Distinguishing gas pain from colic

Gas‑related crying often improves after a good burp or a gentle tummy massage, and the baby may display a “gassy” posture—legs drawn up, a clenched belly, and occasional hiccups. In true colic, the crying persists despite burping and may occur at the same time each day, regardless of feeding.

Practical ways to reduce gas

• Burp your baby after every 2‑3 oz of milk.
• Try “bicycle” leg motions while the baby lies on their back.
• Use anti‑colic bottles or slow‑flow nipples.
• For breastfed infants, ensure a deep latch to limit air intake.

Even when gas is present, it’s usually part of a broader picture that includes other triggers.

Studies from the NHS suggest that parents who combine burping with gentle abdominal massage see a modest reduction—about 15 %—in the duration of crying episodes.

Is colic linked to formula intolerance in newborns?

Formula intolerance, especially to cow‑milk protein, is recognized as a potential driver of colic‑like symptoms. When an infant’s gut reacts to the protein, inflammation can cause bloating, gas, and prolonged crying.

Signs that formula intolerance may be at play

• Frequent, watery stools or stools with blood or mucus.
• Persistent spit‑up that is more than normal reflux.
• Skin eruptions such as eczema or hives.
• Colic that doesn’t improve after feeding adjustments.

What the evidence says

Studies cited by the British National Health Service (NHS) and the American Academy of Pediatrics (AAP) show that switching to a hydrolyzed or soy‑based formula can reduce crying in a subset of infants with suspected protein intolerance. However, the overall benefit is modest, and a trial of a new formula should be done under pediatric guidance.

How to test for intolerance safely

Consult your pediatrician before changing formulas. They may recommend a 2‑week trial of a hypoallergenic formula, monitoring stool patterns and crying duration. If symptoms improve, the intolerance hypothesis gains support.

Remember that any formula change should be gradual to avoid upsetting the baby’s stomach and to give the clinician a clear picture of cause and effect.

How to tell if colic is due to reflux in a newborn?

Both reflux and colic cause crying, but there are subtle clues that point toward reflux as the primary driver.

Key differences

• Timing: Reflux‑related crying often occurs soon after feeding, whereas colic may peak in the late afternoon or evening, independent of meals.
• Physical signs: Look for arching of the back, frequent spit‑up, or a sour taste in the baby’s mouth.
• Positional relief: Babies with reflux may calm when held upright for 20–30 minutes after feeding.

When to consider a reflux evaluation

If your infant shows persistent vomiting, poor weight gain, or chronic coughing, a pediatrician may order a pH probe or recommend medication such as ranitidine (though recent FDA guidance advises caution). Most reflux in newborns resolves as the lower esophageal sphincter matures.

The AAP emphasizes that non‑pharmacologic measures—like smaller feeds and upright positioning—remain first‑line before any medication is considered.

What role does parental stress play in newborn colic?

Parental stress doesn’t cause colic directly, but it can amplify a baby’s crying response and make it harder for parents to soothe their infant. Stress hormones like cortisol can affect milk composition in breastfeeding mothers, potentially altering the infant’s gut microbiome.

Evidence from research

Studies from the World Health Organization (WHO) and the University of Michigan have found that higher maternal stress scores correlate with increased reports of infant colic. While the relationship is not causal, it highlights the importance of caregiver well‑being.

Practical ways to reduce parental stress

• Take short, scheduled breaks—even five minutes of deep breathing can lower cortisol.
• Share nighttime duties with a partner or trusted support person.
• Use a “colic diary” (see below) to track patterns, which often reduces anxiety by providing a sense of control.
• Seek professional help if you notice signs of postpartum depression or anxiety.

Healthcare providers often suggest mindfulness apps or brief walks as low‑effort strategies that have measurable benefits for both parent and baby.

When should I see a doctor for colic in my newborn?

Most colic is benign, but certain warning signs indicate that a medical evaluation is needed.

Red‑flag symptoms

• Fever above 38 °C (100.4 °F) or persistent low‑grade fever.
• Vomiting that looks like “projectile” or contains blood.
• Diarrhea or constipation lasting more than a few days.
• Noticeable weight loss or failure to gain weight.
• Skin changes such as a rash, jaundice, or swelling.
• Any signs of dehydration (dry mouth, fewer wet diapers).

If you observe any of these, contact your pediatrician promptly. Even if the symptoms are mild but you feel uncertain, a quick phone call can provide reassurance and rule out infection, allergy, or anatomical issues.

In the UK, the NHS advises that any fever in an infant under three months warrants immediate medical review, regardless of other symptoms.

How long does colic typically last in newborns?

Colic most often peaks between 4 and 6 weeks of age and begins to improve by 3 months. The classic “colic curve” shows a rise, a plateau, and a gradual decline, with most infants showing marked improvement by 4 months and virtually resolved by 6 months.

Prognosis

Long‑term outcomes are reassuring: studies from the Centers for Disease Control and Prevention (CDC) indicate that colic does not predict later developmental or behavioral problems. The main impact is on parental stress and sleep disruption during the first few months.

What to expect as your baby grows

As the digestive system matures, gas production drops, reflux resolves, and feeding patterns stabilize. By the time your infant reaches the “four‑month milestone,” you’ll likely notice shorter, less intense crying episodes and a more predictable routine.

Parents often report that the “evening crying” pattern fades first, followed by a gradual decline in overall fussiness.

Colic vs. gas pain in newborns: what’s the difference?

Both conditions cause a baby to cry, but the triggers and relief patterns differ.

Colic

• Occurs without a clear cause.
• Cries often follow a daily rhythm (late afternoon/evening).
• Does not reliably improve after burping.

Gas pain

• Directly related to swallowed air or intestinal gas.
• May be relieved by burping, tummy massage, or repositioning.
• Often associated with visible abdominal distention.

Understanding these nuances helps you choose the most effective soothing technique.

In practice, many clinicians advise trying a brief burp and gentle massage first; if the crying persists for the characteristic three‑hour window, colic remains the most likely diagnosis.

Best soothing techniques for colic in newborns

While no single method works for every baby, many parents find relief with the following evidence‑backed strategies.

Swaddling and rhythmic motion

Wrap your baby snugly in a breathable blanket and gently rock or sway. The “in‑womb” feeling can calm the nervous system. The CDC notes that rhythmic motion mimics the prenatal environment and can reduce crying by up to 30 %.

White noise and soothing sounds

Soft “shhh” sounds, white‑noise machines, or recordings of a heartbeat can trigger a calming response. Keep the volume below 50 dB to protect delicate hearing.

Warm baths

A lukewarm bath (around 37 °C) can relax abdominal muscles and ease discomfort. Always test water temperature with your wrist before placing the baby in the tub.

Gentle tummy massage

Clockwise circular motions on the belly, combined with “bicycle” leg movements, can help move trapped gas. Use a tiny amount of baby‑safe oil for smoothness.

Pacifier use

Sucking can provide soothing feedback for many infants. If you’re breastfeeding, offer the pacifier after feeding to avoid nipple confusion.

Combining two or three of these techniques—such as a warm bath followed by white noise—often yields the best results, according to a 2022 AAP review.

Diet changes for breastfeeding mothers to reduce newborn colic

Because breastmilk carries flavor and nutrients from the mother’s diet, certain foods can influence a baby’s digestive comfort.

Common culprits

• Dairy (cow’s milk, cheese, butter)
• Caffeinated beverages
• Cruciferous vegetables (broccoli, cabbage)
• Spicy or heavily seasoned foods

How to test safely

Eliminate one suspected food group for two weeks, then reintroduce it while monitoring your baby’s crying pattern. A clear reduction in colic episodes suggests a link.

Nutrient‑rich alternatives

Replace dairy with fortified soy or almond milks, and choose low‑caffeine herbal teas (e.g., rooibos) if you need a warm drink. Keep calcium intake adequate through leafy greens or supplements as advised by your provider.

Breastfeeding support groups often share printable elimination‑diet charts that make tracking easier for busy parents.

Over‑the‑counter remedies for newborn colic safety

Many parents encounter products marketed as “colic drops,” “probiotic powders,” or “simethicone syrups.” Here’s what reputable bodies say.

Simethicone

Simethicone (e.g., Mylicon) is an anti‑gas agent that is not absorbed systemically. The American Academy of Family Physicians (AAFP) considers it safe for infants, but studies show limited effectiveness for colic.

Probiotics

Specific strains such as Lactobacillus reuteri have shown modest benefit in reducing crying time, according to a Cochrane review. However, product quality varies, so choose a brand with third‑party testing and discuss use with your pediatrician.

Herbal teas and homeopathic remedies

These are not recommended for newborns due to lack of safety data and potential contaminants. The FDA advises against giving any herbal supplement to infants under six months.

Bottom line

Most OTC options provide little more than a placebo effect. Non‑pharmacologic soothing remains the cornerstone of colic management.

When trying any over‑the‑counter product, always check the label for age‑appropriateness and consult your provider if you have doubts.

Signs that colic may indicate an underlying medical condition

While colic is usually benign, certain patterns hint at a deeper issue.

Persistent vomiting or projectile spit‑up

This could signal pyloric stenosis, a condition that requires surgical correction.

Blood in stool or severe diarrhea

These signs may indicate a cow‑milk protein allergy or an infection that needs testing.

Failure to thrive

If weight gain stalls despite adequate feeding, an underlying metabolic or gastrointestinal disorder should be ruled out.

Rash, wheezing, or swelling

These symptoms could point to a food allergy or eczema, which sometimes co‑occurs with colic‑like crying.

If any of these appear, contact your pediatrician promptly for a thorough evaluation.

How to track colic episodes in a newborn diary

Documenting patterns helps you spot triggers and gives your doctor concrete data.

What to record

• Date and time of each crying episode.
• Duration (in minutes) and intensity (scale 1‑5).
• Feeding details: type (breast, formula), amount, and any recent diet changes.
• Positioning, burping attempts, and soothing methods used.
• Sleep patterns before and after the episode.

Tools

Use a simple notebook, a spreadsheet, or a dedicated baby‑tracking app. Consistency over two weeks often reveals a rhythm that you can address.

Many pediatric offices provide printable diary sheets that align with AAP recommendations for monitoring infant feeding and crying.

Impact of sleep patterns on colic severity in infants

Sleep deprivation creates a feedback loop: a tired baby cries more, and more crying disrupts sleep further.

Why sleep matters

The American Academy of Sleep Medicine (AASM) explains that inadequate REM sleep can heighten pain perception, making a baby more sensitive to gastrointestinal discomfort.

Tips to improve sleep

• Establish a calming bedtime routine (dim lights, soft music).
• Encourage “day‑night” cues: keep daytime interactions bright and active, nighttime quiet and low‑light.
• Consider a white‑noise machine to mask sudden noises.
• Swaddle safely to reduce startle reflexes.

Better sleep doesn’t cure colic, but it often reduces the intensity of episodes and helps parents recover.

The gut microbiome and colic: what we know

Emerging research suggests that the composition of an infant’s gut microbiota may influence colic severity. Babies with lower diversity of beneficial bacteria, such as Bifidobacterium, sometimes experience longer crying bouts.

While the science is still evolving, a 2021 review in *Pediatrics* highlighted that probiotic supplementation can modestly improve symptoms, especially when paired with dietary adjustments. However, the evidence is not yet strong enough for universal recommendations.

When to consider a probiotic supplement for colic

If you’ve tried feeding adjustments, soothing techniques, and environmental tweaks without noticeable improvement, a probiotic may be worth discussing with your pediatrician. Look for products containing Lactobacillus reuteri DSM 17938, which has the most robust data.

Typical guidance from the AAP suggests a trial of 4–6 weeks, monitoring crying duration daily. If there’s no change, discontinue the supplement and focus on other strategies. Always choose a reputable brand with third‑party testing to avoid contamination.

Remember that probiotics are not a cure‑all; they work best when combined with a consistent feeding schedule and stress‑reduction practices for the whole family.

Myth vs. fact

Myth: Colic is caused by a mother’s diet alone.
Fact: While certain foods can affect breastmilk, most colic cases have multifactorial origins, and diet changes help only a subset of infants.

Myth: Colic means the baby will have lifelong behavioral problems.
Fact: Research shows colic does not predict later temperament or developmental issues.

Myth: Over‑the‑counter colic drops will stop the crying instantly.
Fact: Most OTC remedies have limited evidence; soothing techniques and routine adjustments are more reliable.

Key takeaways

• Colic follows the “rule of threes” and usually resolves by 4–6 months.
• Common triggers include an immature gut, excess gas, reflux, and formula intolerance.
• Regular, smaller feedings, proper burping, and anti‑colic bottles can reduce air intake.
• A simple diary helps identify patterns and reassures both parents and clinicians.
• Seek medical attention for fever, vomiting, weight loss, or rash.
• Gentle soothing—rocking, white noise, warm baths, and tummy massage—offers the best relief.
• Emerging evidence links gut microbiome diversity to colic severity; consider probiotics after consulting a pediatrician.

Frequently asked questions

What are the signs of colic in a newborn?

Colic is marked by episodes of intense crying for more than three hours a day, three days a week, for at least three weeks, typically occurring in the late afternoon or evening. The baby may clench fists, arch the back, and show limited response to soothing.

How long does colic usually last for babies?

Most colic peaks between four and six weeks of age and gradually improves by three months, with most infants outgrowing it by six months.

Can certain foods cause colic in newborns?

Yes—some breastfed babies react to maternal dairy, caffeine, or spicy foods, while formula‑fed infants may be sensitive to cow‑milk protein. Eliminating a suspect food for two weeks can reveal a link.

When should I be concerned about my baby's colic?

Contact a doctor if the crying is accompanied by fever, vomiting, blood in stool, poor weight gain, rash, or signs of dehydration. These may indicate an underlying medical condition.

Is there a cure for colic in newborns?

There is no single cure, but most infants improve with time and supportive care. Strategies such as consistent feeding schedules, gentle rocking, white noise, and tummy massage can lessen severity.

How can I soothe a colicky baby at night?

Try a combination of swaddling, a soft white‑noise machine, a warm bath before bedtime, and holding the baby upright for 20 minutes after feeding. Keeping the environment dim and calm also helps.

Do probiotics help with colic?

Some studies suggest that specific probiotic strains, especially Lactobacillus reuteri DSM 17938, can reduce crying time modestly. Discuss a trial with your pediatrician and monitor results over a few weeks.

Can colic affect my baby’s growth?

Colic itself does not typically impair growth. However, if a baby is not feeding well because of discomfort, weight gain could be affected. Track weight and feeding patterns, and alert your provider if growth stalls.

When to call your doctor

If you notice any of the following, seek medical attention promptly: fever over 38 °C, projectile vomiting, blood in stool, poor weight gain, persistent rash, signs of dehydration, or if your baby’s crying pattern suddenly changes or worsens.

This article provides general information and is not a substitute for personalized medical advice. Always consult your pediatrician or healthcare provider with specific concerns.

References

1. American Academy of Pediatrics (AAP). “Management of Colic in Infants.” Clinical Practice Guideline, 2022.
2. National Health Service (NHS). “Colic in Babies.” Guidance for Parents, 2023.
3. World Health Organization (WHO). “Infant Feeding Guidelines.” 2021.
4. Centers for Disease Control and Prevention (CDC). “Safe Sleep Practices for Infants.” 2022.
5. American Academy of Family Physicians (AAFP). “Simethicone Use in Infants.” Clinical Recommendations, 2020.
6. Mayo Clinic. “Infant Reflux.” Patient Care Information, 2023.
7. University of Michigan. “Maternal Stress and Infant Colic.” Journal of Perinatal Medicine, 2021.
8. Cooperative Review. “Probiotics for Infant Colic.” Cochrane Database of Systematic Reviews, 2020.
9. Pediatrics. “Gut Microbiome and Infant Colic.” 2021.
10. American Academy of Sleep Medicine (AASM). “Sleep Recommendations for Infants.” 2020.