Infant Colic: Why Your Baby Cries for Hours and What Helps

It is 6pm, dinner is going cold on the counter, and the baby who was calm all morning has been screaming for an hour. Here is what is going on, in numbers first.

• Colic means long bouts of crying in a healthy baby under 5 months, with no cause you can find or fix
• Rule of thumb: more than 3 hours a day, on more than 3 days a week, for at least a week (NHS)
• 17–25% of babies meet that bar in the first 6 weeks, and only 0.6% by 10–12 weeks
• Since 2026 the Rome V criteria no longer use the word colic: the new name is infant distress syndrome

Colic is common, it is exhausting, and it ends. None of that makes 6pm easier, so the rest of this article is about what you can actually do.

With my eldest I went through the whole list. First I thought she was hungry. Then colic. Then teeth. We tried everything I could think of, and honestly, to this day I am not sure what it was. I have written about her nights before; this one is about the crying itself, and what I know now.

Quick reference

Why colic got a new name in 2026

The Rome criteria are the international rulebook doctors use for gut-related symptoms that have no structural cause. The fifth edition, Rome V, came out in 2026, and the child and adolescent paper says it plainly: the term "infantile colic" has been replaced with "infant distress syndrome" (Di Lorenzo et al., 2026). The Rome Foundation describes the whole revision as partly an effort to reduce imprecise or stigmatizing terms (Drossman et al., 2026).

Why does the word matter? Because "colic" sounds like a diagnosis of tummy pain. Parents hear it and start changing formulas, cutting foods, buying drops. The German federal parenting portal points out that only about 5% of babies who cry a lot have a problem with the gut (kindergesundheit-info.de). The new name describes what you see, a distressed baby, without guessing where it comes from.

The guessing was the hardest part for me. Every new explanation meant a new attempt, and when it didn't work, I went looking for the next one. A name that doesn't promise a cause would not have given me my sleep back. It might have let me stop hunting for one.

One honest caveat. The full Rome V criteria sit behind a paywall, and the summaries we could read confirm the new name but do not list the new wording. So below we use the Rome IV definition doctors have worked with since 2016, and say so. Your pediatrician may still say "colic". That is fine. Same baby, same evenings.

What counts as colic

Under Rome IV, a doctor looks for all of these in a baby from birth to 5 months, with the crying starting and stopping inside that window (Benninga et al., 2016):

1. Recurrent, prolonged periods of crying, fussing or irritability that you cannot prevent or settle
2. No failure to thrive, no fever, no illness

Rome IV dropped the strict hour count for everyday clinical use (Muhardi et al., 2022). The 3-3-1 rule, three hours, three days, one week, is still what most leaflets use, and it is a decent yardstick for home.

What it looks like: a red face, clenched fists, legs pulled up to the tummy or a back that arches, sometimes a lot of wind (NHS). Legs pulled up look like tummy pain. They are also just what babies do when they cry hard.

When does it peak, and when does it end?

You will often read that crying peaks at six weeks. The AAP's parent site says colic peaks at about 3 hours a day by 6 weeks and usually stops by 3 to 4 months (HealthyChildren.org).

Here is the part that surprised us. A meta-analysis of 28 diary studies covering 8,690 babies found no universal peak at six weeks (Wolke et al., 2017). Average fussing and crying sat flat at roughly 2 hours a day for the first six weeks, then fell to about 68 minutes by 10–12 weeks. Colic went from 17–25% of babies early on to 11% at 8–9 weeks and 0.6% by 10–12 weeks.

So if week six came and went and nothing changed, you did not miss the turning point. For many babies it simply arrives a little later.

What actually helps

There is no switch that stops colic. There are things that take the edge off, and they work better in combination than alone.

Hold and move. Cuddling, rocking, walking with your baby in a carrier, a gentle sway. Movement plus closeness is the most reliable calming tool parents have.

Feed upright and burp. Holding your baby upright during feeds and burping afterwards reduces swallowed air (NHS). Keep feeding as you normally do.

Steady sound, low light. A fan, white noise, a quiet room. A warm bath helps some babies. Swaddling and a pacifier help others (HealthyChildren.org); stop swaddling once your baby shows signs of rolling.

The probiotic question. One finding is worth knowing. An individual-participant meta-analysis of four double-blind trials found that the probiotic Lactobacillus reuteri DSM17938 cut crying clearly in breastfed babies, with only 2.6 babies needing treatment for one extra success, but showed no significant effect in formula-fed babies (Sung et al., 2018). If your baby is breastfed, it is a reasonable thing to ask your pediatrician about. If your baby is on formula, the evidence is not there yet.

Some evenings none of it works. You will try anything to help your child, and sometimes even all of it is not enough. I know. That is not a sign you are doing it wrong.

Wait or act? A short decision guide

• Crying in bouts, baby feeding and growing well, calm in between: keep soothing, keep notes for a week, mention it at the next check.
• The crying has changed suddenly, or started after about 3 months: book a visit. A new pattern in an older baby is more often something else.
• Lots of spitting up with the crying: read the difference between spitting up and vomiting before you change anything.
• Crying mostly at bedtime: it may be overtiredness rather than colic; see baby crying before sleep and signs your baby is overtired.
• Your child is past the baby months and still cries a lot: that is a different question; see toddler crying all day.
• You are at the end of your rope: that is a reason to act today. More on that below.

Common mistakes

Switching formula every few days. Each switch takes days to judge, and colic eases on its own over the same weeks, so the last formula gets the credit. Change formula only with your pediatrician.

Cutting foods from a breastfeeding diet on your own. Sometimes a doctor suggests a trial without cow's milk. That is a decision for the two of you, not a forum.

Drops, herbs and the osteopath. The NHS lists anti-colic drops and herbal supplements as lacking evidence, and warns that spinal manipulation and cranial osteopathy may hurt your baby (NHS). Skip them.

Doing every evening alone. One adult holding a screaming baby from 5pm to 9pm, every day, for weeks. Nobody is built for that. Trade shifts if you can, even 30 minutes each.

You will notice one thing only in hindsight: the week the evenings got shorter, you were too tired to notice it happening.

When the crying is too much for you

Put the baby down. Safely, on their back, in the cot. Close the door, step outside for five minutes, breathe, drink some water. A crying baby in a safe cot is safe.

Never shake a baby. Not once, not gently. The AAP is blunt about it: shaking an infant hard can cause blindness, brain damage or death (HealthyChildren.org). Anger at 3am is human. It is also the moment to put the baby down and walk away.

If you feel this way most days, tell your pediatrician or your own doctor. Looking after yourself is part of this; realistic self-care for new moms has ideas that fit into a day with a baby in it.

When to call the pediatrician

Call the same day if:

• your baby has a temperature, especially under 3 months (first fever with a tiny baby explains the thresholds)
• the cry is weak, high-pitched or does not sound like your baby
• your baby feeds poorly, has fewer wet diapers or is not gaining weight
• the crying is still going on after 4 months
• you are worried, full stop

For a weak or unusual cry, the NHS advises emergency care rather than waiting (NHS). A week of notes on when the crying starts and how long it lasts makes the visit much shorter; preparing for a pediatric visit with your child's data shows what to bring. For the bigger picture on nights in the first two years, our baby sleep guide 0–2 years puts colic weeks in context.

Frequently asked questions

Is colic caused by gas?
Babies who cry a lot swallow air, so wind is often a result rather than the cause. Only a small share of babies who cry a lot have a real gut problem. That is one reason Rome V dropped the word colic.

Is infant distress syndrome a different diagnosis from colic?
It is the new name in the Rome V criteria, published in 2026, for what used to be called infantile colic. Your pediatrician may use either term. The practical advice has not changed.

How long does colic last?
For most babies it eases after 8–9 weeks and is over by 3–4 months. A few babies take until about 6 months. Crying that is still going strong after 4 months is worth a check.

Should I switch formula if my baby has colic?
Not on your own. Colic improves with time anyway, so a switch can look like it worked when it did not. If your pediatrician suspects a cow's milk protein allergy, they will guide the change.

Do probiotic drops help colic?
One strain, L. reuteri DSM17938, helped breastfed babies with colic in pooled trials. In formula-fed babies the effect was not significant. Ask your pediatrician before starting any supplement.

Can colic start at 3 months?
Colic usually starts in the first weeks. Heavy crying that begins suddenly in an older baby is more often something else, such as illness, reflux or a sleep problem, so have your baby checked.

How KidyGrow helps you

At 7pm you will not remember whether Tuesday was worse than Monday. You log the feeds, the naps and a rough evening in a few taps, and the app remembers what you can't. Once you have at least 7 days of sleep logs, you see the averages for the week. The Tonight plan takes the last 24 hours into account, so a hard afternoon changes what it suggests for this evening. Some weeks show nothing clear, and that is useful too. When you sit down with the pediatrician, you have the week in front of you instead of a blur.

Sources

1. Di Lorenzo C, et al. Lower and Biliary Disorders of Gut-Brain Interaction: Child and Adolescent. Gastroenterology, 2026.
2. Drossman DA, Chang L, Tack J. Disorders of Gut-Brain Interaction and the Rome V Process. Gastroenterology, 2026.
3. Benninga MA, et al. Childhood Functional Gastrointestinal Disorders: Neonate/Toddler (Rome IV). Gastroenterology, 2016.
4. Muhardi L, et al. Update in the prevalence of infantile colic, regurgitation and constipation: implications of the Rome IV criteria. Front Pediatr, 2022.
5. Wolke D, Bilgin A, Samara M. Fussing and Crying Durations and Prevalence of Colic in Infants: Systematic Review and Meta-Analysis. J Pediatr, 2017.
6. Sung V, et al. Lactobacillus reuteri to Treat Infant Colic: A Meta-analysis. Pediatrics, 2018.
7. NHS, Colic
8. American Academy of Pediatrics, HealthyChildren.org: Colic Relief Tips for Parents
9. kindergesundheit-info.de (BIÖG): Das Schreien des Babys