Baby Health · Crying
Baby Colic — Why & How Long
Excessive baby crying. Rule of 3s (Wessel): ≥3 hours/day, ≥3 days/week, ≥3 weeks. Affects ~20% of babies; peaks 6 weeks; resolves 3-4 months. 5 S's soothing (swaddle, side, shush, sway, suck). NICE / NHS / Karp.
Last reviewed 2 June 2026
Baby colic / PURPLE crying
Is this colic — and what helps?
⚠️ NOT colic — red flags
The Period of PURPLE Crying (Ronald Barr)
- Peak of crying around 6–8 weeks, then declines.
- Unexpected — timing unpredictable.
- Resists soothing — nothing reliably works.
- Pain-like face (but baby is not in pain).
- Long lasting — can total 5+ hours daily at peak.
- Evening — often worse late afternoon / evening.
PURPLE is normal infant crying behaviour, not a disorder. It exists across cultures and species — it’s neurodevelopmental, not parenting failure.
What sometimes helps (and what to try)
- The 5 S’s (Karp): Swaddle, Side-lying hold, Shushing (loud), Swinging (rhythmic), Sucking (pacifier or breast).
- Movement — pram walk, baby carrier, drive in the car, bouncy chair.
- White noise — vacuum, hairdryer, fan, white-noise machine.
- Skin-to-skin — especially for the witching hour.
- Warm bath — can interrupt the cycle.
- Probiotic L. reuteri DSM 17938 — some evidence in breastfed babies (Sung 2013 JAMA Pediatr meta-analysis), less clear in formula-fed. Discuss with your GP / health visitor.
- Anti-colic bottles + paced bottle-feeding if bottle-fed.
- Eliminate cow’s milk protein trial — only if other CMPA features (eczema, blood-streaked stool, vomiting, very strong family hx). Speak to GP first; mum eliminates dairy for 2–4 weeks if breastfeeding, or use hydrolysed formula. False-positive elimination is common; don’t restrict the maternal diet without evidence.
- Reflux medication — only with documented severe reflux (see /calculators/baby-reflux). NICE specifically advises AGAINST PPIs / H2 blockers for crying alone.
- Simethicone / gripe water — broadly negative trials but unlikely to harm; placebo effect for parents is real.
- Get a break. If you feel overwhelmed, put baby safely down in the cot, walk into another room for 5 minutes, breathe. Inconsolable crying is a documented trigger for shaken baby syndrome — the “walk away” safety message is in every PURPLE Crying programme.
Take a baby with crying + any of these to A&E / 999:
- Fever in a baby under 3 months (any temp ≥ 38 °C)
- Projectile or green / bilious vomiting
- Blood in vomit or stool
- Lethargic / floppy / hard to rouse between crying
- Non-blanching rash, bulging soft spot, stiff neck
- Difficulty breathing / blue lips
- Single crying spell > 4 hours straight
- You feel you might harm the baby
Common questions about colicky babies
- "Is it definitely colic, or could it be wind?" Tummy issues are over-diagnosed in colic. Crying after every feed with arched back + drawn-up legs is the classic colic posture — but it can also be silent reflux, CMPA, or simply normal crying behaviour. Address feeding mechanics first (latch, paced bottle), then look further if persistent.
- "What about hair tourniquet?" A single strand of mum’s hair can wrap around a baby’s toe, finger, or penis and cause hours of inconsolable crying. Always check carefully — especially if a baby suddenly screams. Easy fix once spotted; medical attention if the hair has cut in.
- "Should I cut out dairy / wheat / spicy food?" Without specific CMPA signs (eczema, blood in stool, vomiting), elimination diets in a breastfeeding mother rarely help colic alone and risk maternal nutrition. Discuss with an IBCLC or paediatric dietitian first.
- "My friend says her baby had reflux and PPIs fixed everything." NICE NG1 + AAP both advise AGAINST PPI / H2 blocker use for crying alone — trials show no benefit over placebo for irritability. Reflux medication is for documented severe vomiting + faltering growth + significant feeding aversion.
- "Will it damage my baby?" No. PURPLE crying is normal neurodevelopmental behaviour and does not harm babies. It damages parents’ sleep, mental health, and relationships — which is why support matters.
- "My partner doesn’t believe colic is real." Show them the Wessel criteria and PURPLE crying framework. Both parents benefit from understanding it’s a phase, not a behaviour problem.
- "How do I survive the witching hour?" Plan for it. Easier dinner. Stronger support adult on duty. Maybe take it in shifts. Walk outside. Movement + low light + skin contact + white noise stacked together work better than any single technique alone.
- "Is my baby in pain?" PURPLE-style crying produces a pain-like face but research suggests babies aren’t in actual pain — just unable to self-regulate the dysregulated state. Pain-presenting crying that’s constant + with vomiting or fever IS pain and needs review.
- "Postpartum depression and crying baby?" Strongly linked — constant crying is a known PPD risk factor. Screen mum (and dad) for depression with EPDS. Getting help for parental mental health helps the whole household.
- "How long does colic actually last?" Peaks at 6–8 weeks; 90% resolved by 12–16 weeks; 95% by 4 months. Persisting crying patterns past 4 months are NOT typical colic and need investigation.
- "What if I shake my baby?" If you feel you might harm your baby, put them safely in the cot, walk to another room, call a friend, call your GP, or call NSPCC (UK 0808 800 5000) / Childhelp (US 1-800-422-4453). Inconsolable crying is THE most common trigger for shaken baby syndrome — you’re not alone in feeling overwhelmed.
- "Does my baby cry less if I breastfeed vs formula feed?" No reliable difference for colic. Both groups follow the PURPLE curve. Don’t change feeding method just for crying.
Educational tool only — not medical advice. Fever in a baby under 3 months, projectile or green vomiting, blood in stool / vomit, lethargy, or breathing difficulty are emergencies — do not assume colic.
What does this mean?
About 1 in 5 healthy babies has a phase of intense crying that meets the classic “rule of 3s” (Wessel 1954, still the working definition): crying for at least 3 hours a day, 3 days a week, for at least 3 weeks, in an otherwise well baby. The pattern peaks at 6–8 weeks and resolves by 12–16 weeks in 90% of babies, regardless of what you try. Ronald Barr’s Period of PURPLE Crying framework (Peak, Unexpected, Resists soothing, Pain-like face, Long lasting, Evening) reframes this not as a disorder but as a normal neurodevelopmental phase — it occurs across cultures and species and is not caused by parenting. The hardest truth is that nothing dramatically shortens it. What does help is making it bearable: the 5 S’s (Karp — swaddle, side-lying hold, shush, swing, suck), movement, white noise, skin-to-skin, sometimes the probiotic L. reuteri DSM 17938 in breastfed babies (Sung 2013 JAMA Pediatr meta-analysis showed modest benefit). What doesn’t reliably help: anti-reflux medication for crying alone (NICE + AAP advise against), maternal elimination diets without specific CMPA signs, simethicone / gripe water. The most important safety message is walk away when overwhelmed: inconsolable crying is the most common trigger for shaken baby syndrome. Putting your baby safely in the cot and stepping into another room for 5 minutes is good parenting, not failure. Critical to know: certain signs are NOT colic and need same-day medical assessment — fever in any baby < 3 months, projectile or green vomiting, blood in stool or vomit, lethargy between crying spells, non-blanching rash, bulging soft spot, breathing difficulty, single crying spell > 4 hours, or new/worsening crying past 4 months. Always check for the hidden hair tourniquet (a single strand wrapped around a toe, finger, or genitals) — quick to find and fix, devastating if missed.
Is my baby colicky?
Wessel rule of 3s: crying ≥3 hours/day, ≥3 days/week, for ≥3 weeks in an otherwise well baby. Starts 2-3 weeks; peaks 6 weeks; resolves 3-4 months. ~20% of babies.
5 S’s soothing
- Swaddling.
- Side position (in arms).
- Shushing (white noise).
- Swaying / gentle rocking.
- Sucking (pacifier or feeding).
Also: warm bath, massage, carrier, car ride, fresh air walk.
Colic vs reflux
- Reflux: tied to feeds; spitting; back-arching with feeds.
- Colic: not feed-tied; evening episodes; legs drawn up.
Many babies have both.
Could it be CMPA?
~10% of colicky babies. Signs: colic + reflux + eczema + loose / blood-stained stools + poor weight gain. Trial: 2-3 week elimination diet (mum if breastfeeding; hydrolysed formula).
When to see GP
- Fever >38°C.
- Poor feeding.
- Vomiting (not just spit-up).
- Blood in stool.
- Weight loss / poor gain.
- Projectile vomiting.
- High-pitched abnormal cry.
- Parent mental health suffering.
Treatments
- Infacol (simeticone) — first-line; modest evidence.
- L. reuteri probiotic (Biogaia) — some evidence for breastfed.
- Anti-colic bottles, gripe water — minimal evidence.
- Infant massage + carrier wearing — evidence-based.
Parent mental health
PND rates ~30% in colicky-baby parents (vs 15% baseline). Cry-Sis UK helpline 08451 228669. Pandas Foundation. Take breaks. Put baby in safe place if needed. NEVER shake baby.
Different scenarios
Scenario 1: 6-week-old, evening crying 4h/day
Classic colic. 5 S's. Will resolve by 3-4 months.
Scenario 2: Crying + spitting + eczema + blood in nappy
CMPA suspected. Elimination diet trial.
Scenario 3: Crying + fever + poor feeding
NOT just colic. Same-day GP / 111.
Scenario 4: Parent mental health declining
GP. PND screening. Cry-Sis. Support network.
Scenario 5: Reaching breaking point
Put baby in safe place. Step away. Call partner / family / Cry-Sis. NEVER shake.
Care guidance — colic
- Resolves by 3-4 months for most.
- 5 S's evidence-based.
- CMPA + reflux differentials.
- Protect parent mental health.
- Cry-Sis 24h support.
- NEVER shake baby — safe place + step away.
- Red flags = same-day medical review.
Sources
- Wessel MA, et al. Paroxysmal fussing in infancy, sometimes called "colic". Pediatrics 1954.
- NICE CKS. Colic infantile.
- Karp H. The Happiest Baby on the Block.
- Cry-Sis UK. cry-sis.org.uk.
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Frequently asked questions
Is my baby colicky?
RULE OF 3s (Wessel 1954 — still the standard): crying ≥3 HOURS A DAY, ≥3 DAYS A WEEK, for ≥3 WEEKS in an OTHERWISE WELL-FED + HEALTHY baby. Typically starts at 2-3 WEEKS, peaks 6 weeks, resolves 3-4 MONTHS. BABY appears in distress; clenched fists; pulled-up legs; red face; arched back; inconsolable. NOT 'something wrong with you' — common: ~20% of babies.
When does colic start and end?
STARTS: 2-3 weeks of age. PEAKS: ~6 weeks (hardest). RESOLVES: 3-4 months (most by 4 months; almost all by 5 months). DAILY pattern: often WORST evening / late afternoon ('witching hour'). Doesn't have to follow exactly — varies between babies. GOOD NEWS: definite end-point — colic resolves.
What causes colic?
UNCLEAR — multiple theories: (1) IMMATURE digestive system; (2) GUT MICROBIOME developing; (3) NEUROLOGICAL immaturity (overstimulation); (4) FOOD ALLERGY (CMPA — cow's milk protein allergy) in ~10%; (5) REFLUX overlap (~20% have GORD too); (6) PARENT STRESS / feeding tension (chicken-and-egg); (7) NORMAL temperament variation. PROBABLY combination + individual variation. NOT YOUR FAULT.
Best soothing for a colicky baby?
5 S's (Karp): (1) SWADDLING — secure wrap; (2) SIDE position (in arms — not for sleep); (3) SHUSHING — white noise / vacuum cleaner / hairdryer; (4) SWAYING — gentle rocking; (5) SUCKING — pacifier or feeding. ALSO: (6) WARM bath; (7) MASSAGE; (8) BABY CARRIER (movement + closeness); (9) WHITE noise; (10) CAR ride; (11) GENTLE bouncing on exercise ball; (12) FRESH AIR walk. WORKS for some; not all. ROTATE techniques.
Colic vs reflux — how to tell?
REFLUX: more associated with FEEDING — coughing, gagging, arching during/after feeds; SPITTING UP frequent; POOR weight gain sometimes; back-arching with feeds. COLIC: not directly tied to feeds; episodic crying often EVENING; tightening, drawing up legs. OVERLAP — many babies have BOTH. /calculators/baby-reflux for reflux detail.
Could it be cow's milk allergy (CMPA)?
MAYBE — ~10% of colicky babies have CMPA. SIGNS: persistent crying + colic + reflux + ECZEMA + LOOSE / blood-stained stools + slow weight gain. TRIAL: in BREASTFED baby — mum eliminates dairy 2-3 weeks (also soy if persistent). In FORMULA-FED — switch to extensively hydrolysed formula. IF IMPROVES — CMPA likely; allergy clinic referral. NICE recommends 4-week elimination diet trial then re-challenge.
When should I see the doctor?
(1) FEVER (>38°C); (2) POOR feeding; (3) VOMITING (not just spit-up); (4) BLOOD in stool; (5) WEIGHT LOSS or POOR GAIN; (6) PROJECTILE vomiting (pyloric stenosis); (7) HIGH-PITCHED, abnormal cry; (8) CHANGE in usual pattern; (9) PARENT MENTAL HEALTH suffering — exhaustion + low mood; (10) CONCERN about your ability to cope. GP / health visitor / NHS 111. NEVER 'just colic' if anything else changed.
Does Infacol / Dentinox / probiotics help?
(1) INFACOL (simeticone) — anti-gas; modest evidence; safe; NHS first-line often. (2) DENTINOX — combination simeticone + activated charcoal; similar. (3) LACTOBACILLUS REUTERI (Biogaia drops) — some evidence for breastfed colicky babies; modest. (4) GRIPE WATER — herbal; minimal evidence; bicarbonate concern. (5) ANTI-COLIC bottles — minimal evidence. TRY 1-2 weeks; if no help, stop. INFANT MASSAGE + carrier wearing also evidence-based.
What about purple crying / period of purple crying?
PURPLE CRYING — concept by Dr Ronald Barr. PURPLE acronym: PEAK around 6 weeks; UNEXPECTED bursts; RESISTS soothing; PAIN-LIKE face (but not in pain); LONG-LASTING (5+ hrs/day); EVENING. NORMAL developmental phase; resolves. UNDERSTANDING REDUCES PARENT GUILT + frustration. NEVER shake baby — major brain injury.
Could colic affect bonding?
POTENTIALLY YES — relentless crying erodes parent-baby relationship temporarily. PARENT EXHAUSTION + FRUSTRATION normal. STRATEGIES: take breaks (partner / family); skin-to-skin in calm moments; protect own mental health (sleep, food, support); peer support; BABY SAFE PLACE (in cot) if you need to step away. ALWAYS SAFE to put baby down in safe place + step away for few minutes. NEVER shake baby.
How does this affect my mental health?
PARENTAL POSTNATAL DEPRESSION rates higher among colicky-baby parents (~30% vs ~15% baseline). PARTNER affected too. SLEEP DEPRIVATION compounds. STRATEGIES: PND screening (EPDS, PHQ-9); GP if struggling; perinatal mental health team; Cry-Sis UK 24h helpline (08451 228669); Pandas Foundation. PARTNER + family rallying critical. SEEK help early — colic 'resolves' but mental health impact lingers.
What if nothing helps?
VALIDATE: not every baby responds to standard techniques. PROFESSIONALS to consult: HV; GP; sometimes paediatrician; lactation consultant (if breastfeeding issues); CMPA dietitian; cranial osteopath / paediatric chiropractor (mixed evidence; some parents swear by it). MIXED conventional + complementary approaches. ULTIMATELY: time resolves; baby outgrows it. SUPPORT yourself + partner.
Can I prevent colic next baby?
PARTIALLY. RECURRENCE varies. (1) FEEDING — paced bottle feeding; proper breastfeeding latch; (2) AVOID overfeeding; (3) WIND baby after feeds; (4) RESPONSIVE care — pick up sooner; (5) CARRIER from start; (6) WHITE noise; (7) AVOID overstimulation; (8) IF SUSPECTED CMPA history — discuss with HV / dietitian. NOT GUARANTEED prevention — biology factors. Knowing what to expect + support network in place helps.
Is it dangerous for baby?
NO physical harm from colic itself. BABIES outgrow it without lasting effects. NO INCREASE in long-term development issues. The danger: PARENTAL responses (shaking, anger) — NEVER acceptable; reach out for help. SHAKEN BABY SYNDROME causes catastrophic brain injury. ALWAYS put baby in safe place + take break if reaching limit.
How does this relate to other calculators on BumpBites?
Companion: /calculators/baby-reflux; /calculators/breastfeeding-latch; /calculators/infant-formula; /calculators/sleep-schedule; /calculators/postpartum-depression-quiz; /calculators/postpartum-mood-warning; /calculators/baby-cough.