Quick answer: Colic typically peaks at 6 weeks and resolves significantly by 3–4 months, with most babies completely better by 5 months. If you are in the 6-week peak right now, the timeline is finite — even when it doesn’t feel that way.
The standard definition and what it actually tells us
Colic is defined clinically by the Wessel criteria — the ‘Rule of Threes’: crying for more than 3 hours per day, more than 3 days per week, for more than 3 weeks, in an otherwise healthy, well-fed infant. This definition describes a behaviour pattern, not a disease. Approximately 10–40% of babies meet this definition at some point in the first 3 months — the range reflects different diagnostic thresholds. The diagnosis requires ruling out organic causes (milk protein allergy, reflux disease, hernia, UTI) rather than just assuming the crying is ‘normal colic.’
The crying arc: what to expect week by week
Colic crying follows a predictable arc in most babies: Week 1–2: crying seems manageable, within ‘normal’ ranges. Week 2–6: crying intensifies progressively — this is the hardest part and the period when parents most need support. Week 6: peak. This is the week that most parents remember as the worst. Evenings are usually the worst time (sometimes called the ‘witching hour,’ typically 5pm–11pm). Week 7–12: gradual but real improvement — most families notice the evenings getting easier. Week 12–16: most babies are dramatically better; the daily crying arc changes character. By 5 months: essentially all colic has resolved.
Why the evening is always the worst
The evening peak in colic crying is universal enough that it’s been documented across cultures. Proposed explanations include: accumulation of sensory stimulation throughout the day reaching the newborn nervous system’s tolerance limit; maternal cortisol levels peaking in late afternoon and passing to breast milk; cluster feeding behaviour as babies load up calories for a longer night stretch; and the natural end-of-day cortisol rise in newborns that peaks around 5–7pm. Understanding that the evening peak is biological and predictable — not something you caused or can completely prevent — helps with the psychological load of managing it.
What actually helps
The 5 S’s (Harvey Karp): swaddle, side/stomach position for holding, shushing (loud white noise), swinging (rapid small-amplitude jiggling), sucking — applied together and with intensity matching the baby’s distress. Lactobacillus reuteri DSM 17938 probiotic drops have the best evidence base of any intervention: multiple randomised trials show approximately 50 minutes reduction in daily crying time for breastfed babies with colic. Simethicone (gas drops) — widely used, no better than placebo in clinical trials, but harmless. Passing the baby to a different caregiver — parental stress elevates cortisol that babies detect; a fresh, calm pair of arms sometimes works where exhausted parents have not. Walking outside — movement and change of environment works for many babies. The single most important practical advice: put the baby down safely in the cot and step away for 5–10 minutes when you reach your limit. This is not abandonment — it is harm prevention.
Frequently Asked Questions
My baby is 10 weeks old and still has colic — is that normal?
Yes — while many babies are improving by 8–10 weeks, 10 weeks is still within the normal colic window. The majority of babies are significantly better by 12 weeks. If yours isn’t, it’s worth revisiting whether there’s an organic cause (cow’s milk protein allergy, reflux) that’s been missed.
Could my diet (if breastfeeding) be causing colic?
In a subset of cases, yes — cow’s milk protein in breast milk can cause GI symptoms in sensitive babies. Signs that suggest dietary cause rather than ‘functional’ colic: blood in the stool, significant eczema alongside the crying, family history of milk allergy. A 2–4 week strict dairy elimination trial (all dairy, including traces in bread and biscuits) while continuing to breastfeed can help identify this. Most colic does not have a dietary cause.
Is colic worse at night?
Not necessarily — colic peaks in the evening (5pm–midnight) rather than specifically at night. The predictable evening timing is actually useful: you know roughly when the hard part of the day is coming, which allows preparation (tag-team with a partner if possible, have dinner early, set expectations for a difficult evening).
Related Reading
- Colic in babies: what it is, what helps and what doesn’t
- Surviving colic: a letter to the parent at their limit
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