Most babies grow out of colic between 3 and 4 months of age. About 90% of infants with colic see their symptoms resolve completely by that point. The worst of it typically hits around 6 weeks old, so if you’re in the thick of it right now, you’re likely closer to the end than you think.
The Typical Colic Timeline
Colic follows a surprisingly predictable arc. It usually begins in the first few weeks of life, intensifies around 6 weeks, and then gradually tapers off. Most pediatricians consider 12 weeks the turning point where symptoms meaningfully decline. By 3 to 4 months, the prolonged crying episodes have stopped for the vast majority of babies.
The formal definition of colic, sometimes called the “rule of three,” describes crying that lasts more than three hours per day, happens more than three days per week, and persists for longer than three weeks. If your baby fits that pattern but is otherwise healthy, gaining weight, and feeding normally, colic is the most likely explanation.
For premature babies, the timeline follows adjusted age rather than the date of birth. So a baby born four weeks early would be expected to peak around 10 weeks after birth (6 weeks adjusted) and resolve around 4 to 5 months after birth (3 months adjusted).
Why Colic Happens in the First Place
No one has identified a single cause, but the gut plays a central role. Babies with colic have measurably different intestinal bacteria compared to babies without it. Specifically, colicky infants have significantly fewer beneficial bacteria in the group that includes Bifidobacteria. In one study, the median abundance of Bifidobacterium dropped from about 10% in non-colicky babies to just 0.3% in those with colic. At the same time, certain less desirable bacteria showed up far more often in colicky infants.
This bacterial imbalance is linked to gut inflammation, which researchers have confirmed by measuring inflammatory markers in stool samples. The inflammation likely contributes to the abdominal discomfort that drives the crying. As a baby’s digestive system matures over the first few months and beneficial bacteria establish themselves, the inflammation eases and the colic resolves. This natural maturation process is why colic is self-limiting.
What Can Help While You Wait It Out
Even though colic resolves on its own, weeks of inconsolable crying feel endless. A few approaches have evidence behind them.
One specific probiotic strain has shown consistent results in clinical studies. In a real-world trial, breastfed colicky infants given this supplement saw their average daily crying time drop from roughly 4 hours to under 1 hour over the course of the study. The effect is thought to work by helping restore the balance of gut bacteria that colicky infants are missing. Ask your pediatrician whether a probiotic supplement makes sense for your baby.
If you’re breastfeeding, your diet may matter more than you’d expect. In a controlled trial, mothers who removed common allergens from their diet (dairy, soy, wheat, eggs, peanuts, tree nuts, and fish) saw their babies’ crying decrease by about an hour and a half per day on average. Nearly three quarters of babies in the elimination group improved by at least 25%, compared to just over a third in the control group. You don’t necessarily need to cut everything at once. Many parents start by removing dairy for a week or two to see if it makes a difference.
When the Crying Might Not Be Colic
Colic is a diagnosis of exclusion, meaning it only applies when nothing else is wrong. A few conditions can mimic colic but require different attention.
Cow’s milk protein allergy overlaps significantly with colic symptoms. Both cause abdominal pain, back arching, and drawing the legs up while crying. But milk allergy often comes with additional signs: skin issues like eczema or rashes (in 20 to 25% of affected infants), frequent regurgitation or vomiting (around 30%), blood-streaked stools (about 6%), or persistent diarrhea and constipation. If your baby has any of these alongside the crying, the issue may be an allergy rather than simple colic.
Crying accompanied by fever, lethargy, breathing difficulty, a rash, vomiting, diarrhea, or poor weight gain warrants prompt medical evaluation. These symptoms point to something other than colic and should not be attributed to it.
The Toll on Parents Is Real
If colic is making you feel desperate, anxious, or depressed, that reaction is both common and measurable. Mothers of colicky infants score significantly higher on postpartum depression screening tools than mothers of non-colicky babies, with average scores roughly 60% higher in one study. Among mothers of colicky infants, nearly one in four showed scores suggesting possible depression, compared to one in ten among other mothers.
The fact that colic is “benign” from a medical standpoint doesn’t mean it’s benign for your mental health. Taking shifts with a partner, using ear protection to reduce the sensory intensity of crying, and putting the baby down in a safe space when you need a break are not signs of failure. They’re how you get through the weeks between now and the 3-to-4-month mark when, for 9 out of 10 families, the crying finally stops.