Your baby has been screaming for two hours. You have tried feeding, winding, rocking, walking, singing, the vacuum cleaner noise on YouTube, and just standing in the kitchen holding them in increasing desperation. Nothing works. Your partner is in tears. You feel completely useless.
Welcome to colic. It is brutal, it is bewildering, and it affects roughly one in five babies. This baby colic guide will tell you what colic actually is, what the research says about why it happens, what genuinely helps (and what does not), and how to keep yourself sane until it ends.
Because it does end. That is the one thing worth holding onto.
What Colic Actually Is: The Rule of Three
Colic is not a disease. It is a description. In 1954, a paediatrician named Morris Wessel defined it using what became known as the Rule of Three: a baby has colic if they cry for more than 3 hours a day, more than 3 days a week, for more than 3 weeks in a row, with no identifiable medical cause.
That last part matters. Colic is a diagnosis of exclusion. You only call it colic once you have ruled out everything else: hunger, overfeeding, reflux, cow's milk protein allergy, infection, injury. The Rule of Three is a framework, not a magic wand. If your baby hits those thresholds but something still feels wrong, keep pushing with your GP.
The typical picture looks like this: a baby who is otherwise healthy and feeding well, who seems fine during the day, and then around 5 to 7pm erupts into sustained, inconsolable crying. Legs drawn up. Back arched. Fists clenched. Face red. The crying is high-pitched and relentless, and nothing you do makes a meaningful difference. It usually peaks around 6 weeks of age.
Colic affects boys and girls equally. It does not matter whether the baby is breastfed or formula-fed. It cuts across income brackets and parenting styles. It is not your fault, and it is not a sign that anything is wrong with your baby long-term.
What Causes Colic? (Honest Answer: Nobody Fully Knows)
Decades of research and there is still no consensus. That is frustrating but worth knowing upfront, because it explains why there is no reliable cure. Here are the leading theories.
1. An Immature Gut Microbiome
The most compelling current theory is that colicky babies have a different gut microbiome composition compared to non-colicky ones. Specifically, they tend to have fewer Lactobacillus bacteria and more gas-producing bacteria. This imbalance may cause intestinal discomfort, which drives the crying.
This theory is supported by studies showing that Lactobacillus reuteri, a specific probiotic strain, reduces crying time in some colicky breastfed babies. It does not work for everyone, but the mechanism is biologically plausible. More on this in the treatment section.
2. Overstimulation of the Developing Nervous System
Newborns have immature neurological systems. Some researchers believe colicky babies are more sensitive to sensory input and reach an overload threshold more easily. The evening timing fits: after a full day of stimulation, the nervous system hits capacity and the crying is essentially a system reset.
This theory aligns with the concept of PURPLE crying, which we will cover below. It also explains why the evening pattern is so consistent across cultures and parenting styles.
3. Cow's Milk Protein Sensitivity
In a subset of colicky babies (estimates vary from 5 to 15 percent), the culprit is sensitivity or intolerance to cow's milk protein. For formula-fed babies, this means the protein in standard formula. For breastfed babies, it can mean cow's milk proteins from the mother's diet passing into breast milk.
If cow's milk protein is the cause, switching to a hydrolysed formula or eliminating dairy from the mother's diet can make a significant difference within one to two weeks. This is worth trialling if other interventions are not helping.
4. Gas and Digestive Discomfort
The classic image of colic, legs drawn up and a hard-looking belly, has long been blamed on gas. The current thinking is that gas is more likely a symptom of the crying (swallowing air while crying) than a primary cause. But digestive immaturity is real, and some babies do seem to have more trouble processing feeds than others.
PURPLE Crying: A More Useful Framework
The National Centre on Shaken Baby Syndrome developed a framework called PURPLE crying to describe the normal (if extreme) crying behaviour of young babies. PURPLE is an acronym:
- P - Peak of crying (peaks around 2 months, then reduces)
- U - Unexpected (comes and goes with no obvious reason)
- R - Resists soothing (nothing seems to work)
- P - Pain-like face (looks like pain even when there is none)
- L - Long-lasting (can go on for hours)
- E - Evening clustering (worse in the late afternoon and evening)
PURPLE crying matters because it reframes colic as a normal developmental phase rather than a medical crisis. It also gave us research showing that explaining this framework to parents significantly reduces the risk of shaken baby syndrome, because frustrated carers are more likely to put the baby down safely and walk away when they understand that the crying is normal and will pass.
If you are reaching the edge of your patience, put the baby down somewhere safe and take five minutes. That is not giving up. That is being a responsible parent.
What Actually Helps: Evidence-Based Treatments
Let's be honest: the evidence base for colic treatments is fairly thin. Most trials are small, poorly designed, or show effects that do not replicate. Here is an honest breakdown.
Probiotics (Lactobacillus reuteri)
This is the strongest evidence we have for any intervention. Multiple randomised trials have shown that L. reuteri drops (brand names include BioGaia) reduce crying time in breastfed babies with colic. One systematic review found it reduced crying by around 49 minutes per day compared to placebo.
The caveat: it works less reliably in formula-fed babies, and the effect size varies between studies. It is generally safe. Worth trying, particularly if you are breastfeeding. Talk to your GP or health visitor before starting.
Feeding Position Changes
If you are bottle-feeding, try paced bottle feeding. Hold the baby more upright, use a slow-flow teat, and take regular breaks mid-feed to wind. This reduces the amount of air swallowed during feeds, which reduces gas and can help.
For breastfed babies, try varying feeding positions and ensure a good latch. A poor latch means the baby takes in more air alongside the milk. A lactation consultant can spot problems that are not obvious to parents. If your partner is breastfeeding, read our guide on how dads can support breastfeeding for practical ways to help.
Wind Relief Techniques
Regular winding during and after feeds is the baseline. The over-the-shoulder position, the sitting-up pat, and the face-down across-the-lap method all have their advocates. No single method is consistently superior. Try them and see what your baby responds to. The key is consistency and patience rather than the specific technique.
Carrying and Motion
Babywearing and rhythmic motion (walking, rocking, car rides, white noise) provide genuine short-term relief for many colicky babies. This does not fix colic, but it reduces the duration and intensity of crying bouts. A structured sling or carrier lets you do this without destroying your back and arms over a four-week stretch. If you are new to carriers, our babywearing guide for dads covers the options worth considering.
Dietary Changes (Cow's Milk Protein)
If you suspect cow's milk protein sensitivity, a two-week elimination trial is reasonable. Breastfeeding mothers can cut dairy from their diet completely (be meticulous, it hides everywhere). Formula-fed babies can switch to a hydrolysed protein formula on GP advice. If colic improves significantly within two weeks, you have your answer.
More than just colic to navigate right now?
The full Playbook covers everything from the first week home to the toddler years. Evidence-based, no fluff.
Get The New Dad Playbook - £27.99What Does Not Help (Despite What Everyone Will Tell You)
Gripe Water
Gripe water has been sold as a colic remedy for over 150 years. The clinical evidence for it is poor. Randomised controlled trials consistently show it performs no better than a placebo. Most formulations contain fennel, ginger, or chamomile extracts, none of which have robust evidence behind them for colic.
It is not harmful in most cases, and some parents feel it helps. It probably does not, but the ritual of administering it involves holding, calming, and feeding the baby, which are the things that actually provide short-term relief. If it gives you something to do and does not break the bank, that is fine. Just do not expect it to solve anything.
Simethicone Drops (Infacol, Mylicon)
Simethicone is an anti-foaming agent that breaks up gas bubbles in the gut. It is widely recommended and widely used. The trials, however, show it is no more effective than placebo for colic. If gas were the primary cause of colic, this would work. The evidence suggests gas is more symptom than cause.
Again, safe to use, but do not expect a miracle. NHS guidance does not recommend it as a first-line treatment.
Lactase Drops
Lactase drops are designed to help lactose-intolerant babies digest breast milk. True lactose intolerance in newborns is very rare. These drops are rarely helpful for standard colic and are not recommended without a specific clinical reason.
Chiropractic or Osteopathic Manipulation
Some practitioners market spinal manipulation for colic. The evidence does not support this. A 2012 Cochrane review found no good evidence that it is effective. There are also safety concerns with any physical manipulation of infants. Skip this one.
The Emotional Toll: What Nobody Warns Dads About
Here is the thing nobody puts in the parenting books: colic is genuinely traumatic for parents. Not metaphorically. Research shows parents of colicky babies experience significantly higher rates of anxiety, depression, relationship strain, and in extreme cases, intrusive thoughts about harming the baby. Those thoughts do not make you a bad parent. They make you an exhausted one. But they are a signal to get help.
Dads often feel this particularly acutely because of the helplessness dimension. You cannot fix it. Your job, as you have probably understood it for your whole adult life, is to identify problems and solve them. Colic laughs at that. The more you try to find the right trick, the more defeated you feel when it does not work.
Read about new dad anxiety if any of this resonates. What you are feeling is not weakness. It is a normal response to an abnormal level of sustained stress.
A few things that actually help parents (not the baby, you):
- Shift rotation. If there are two of you, agree on who is on duty and when. Knowing you get a break is almost more important than the break itself. Our guide on how to split night feeds as a couple has a practical framework for this.
- Tag out without guilt. When you hit your limit, hand the baby over and leave the room. The baby is not better off with a parent who is about to lose it.
- Lower the bar on everything else. The house, the meals, the social obligations. None of it matters right now.
- Be honest with your GP. If you are struggling mentally, say so. Postnatal depression affects dads too, and colic is a significant trigger.
Also worth reading: our full guide to why your baby might be crying if you want a structured way to work through the possibilities before landing on colic as the explanation.
Getting Enough Sleep While Managing Colic
Colic and sleep deprivation compound each other viciously. A baby who cries for three hours every evening disrupts the entire household's sleep routine. Your decision-making degrades, your patience thins, and your ability to cope with the next crying bout drops with every lost hour of rest.
This is covered in more depth in our newborn sleep schedule guide, but the short version is: prioritise the adults sleeping in shifts, even if the environment feels chaotic. Two four-hour blocks of sleep beats eight hours of broken dozing. Protect your sleep like it is a medical intervention, because during colic, it basically is.
The Colic Cry vs. Other Cries
One of the hardest parts is knowing whether what you are hearing is colic or something that needs medical attention. Here is a rough guide.
Colic crying tends to be: predictable in timing (usually evening), high-pitched and intense, sustained despite soothing, accompanied by physical tension (arched back, clenched fists), but present in a baby who is otherwise feeding well and gaining weight normally.
See a GP urgently if the cry is accompanied by: fever over 38C in a baby under 3 months, vomiting (not just posseting), blood in the nappy, significant changes in feeding or wet nappies, unusual high-pitched or weak cry, visible distress beyond the usual colic pattern, or if your gut tells you something is actually wrong. Trust that instinct. You know your baby.
Also see our guide on how to soothe a crying baby for a broader toolkit of techniques beyond colic specifically.
When to See Your GP About Colic
You should see a GP when:
- You cannot rule out a medical cause for the crying
- The baby is not gaining weight adequately
- You want to trial a hydrolysed formula (requires guidance)
- You want to try Lactobacillus reuteri and want professional input first
- You or your partner are struggling to cope mentally
- You just need to hear from a professional that your baby is okay
That last one is completely valid. GPs understand that a reassurance appointment for an exhausted parent of a colicky baby is time well spent. Go.
It Ends. I Promise.
Colic almost always peaks around 6 weeks and resolves by 3 to 4 months. By 5 months, the vast majority of colicky babies have stopped entirely. There are no long-term developmental consequences. Babies who had colic are not more likely to have behavioural problems, attachment issues, or any other negative outcomes.
Right now that timeline might sound impossibly far away. At 2am with a screaming baby who has been at it for three hours, four months feels like a geological era. But it is a finite problem with a guaranteed end date. That is actually quite rare in parenting. Lean into it.
You are going to get through this. Not because you found the perfect technique or the right combination of drops, but because you kept showing up, kept trying, kept putting the baby down when you needed to, and kept going. That is what good parenting looks like during colic. Messy, exhausted, and present.
"The crying will stop. It always stops. And one day you'll barely remember how loud it was."