A guide to colic in babies: Understanding the gut connection

By: Dahlia Rimmon MS, RDN

Medically reviewed by: Jennifer Agha-Khan MS, RDN

If your baby has colic, you know it. The constant crying, sleepless nights, disrupted routines, and the overwhelming stress can leave everyone in the household feeling exhausted and miserable. Worst of all, it may seem like all your solutions make no difference at all.

Fortunately, you're not alone. Colic is a common condition that affects roughly 20% of newborns and infants. Although its exact cause is not fully understood, the silver lining is that colic is temporary. That said, “temporary” doesn’t make it any easier to cope with, and no parent should feel like they’re stuck managing it for weeks (or months!) on end.

In this guide, we’ll dive into what colic is, explore possible causes, and explain how supporting your baby’s gut health could be the key to the comfort and relief you’ve been looking for.

What is colic in babies and what are the symptoms?

Colic occurs when a baby cries persistently and inconsolably, often for no clear reason, for three or more hours a day. The crying is usually loud, high-pitched (sometimes full-on screaming), and difficult to soothe, which can be incredibly frustrating and distressing for parents. Colic typically starts within the first few weeks after birth, peaks around six weeks, and most babies outgrow it by 3 to 4 months. In some cases, symptoms can last up to 6 months.

Many parents notice that colic symptoms hit hardest in the late afternoon or evening (often between 6pm and midnight). During these episodes, babies may pull their legs toward their tummy, pass gas, turn red in the face, and seem tense and uncomfortable. Unfortunately, traditional soothing and comforting offer little relief during colic episodes.

And if you’re wondering how colic is different from the usual fussiness caused by tiredness, hunger, or a wet diaper, the differentiating factor is the “rule of 3’s.” Babies with colic cry for at least three hours a day, three or more days a week, for three weeks or longer.

What causes colic?

The truth is, no one knows exactly why colic happens. Research is still limited, and studies often show mixed results. That said, experts think several factors could play a role, including:

• Abdominal discomfort or digestive issues

• Incorrect feeding techniques (like improper latch)

• Overfeeding or underfeeding

• Maternal diet (for breastfed babies)

• Food allergies or sensitivities, such as lactose intolerance or milk protein intolerance

• Insufficient burping after feeds

• Sensitivity to stimulation

• Difficulty self-soothing or regulating the nervous system

• Illness

• Gut inflammation

• Imbalances in the gut microbiome

• Swallowing excess air and gas

• Gastroesophageal reflux

The connection between gut health and colic

While the exact cause of colic isn’t fully understood, emerging research suggests that babies with colic may have gut dysbiosis, an imbalance in the community of microorganisms in their digestive system. This happens when there are more “bad” bacteria than “good,” or there is an overproduction of pathogenic microorganisms in the gut. “We know that there are gut microbiome differences between babies with and without colic, in particular babies with colic tend to have lower levels or lack Bifidobacterium and other lactic acid bacteria,” explains Dr. Diana Taft, PhD, Assistant Professor, Food Science and Human Nutrition Department, University of Florida.

Scientists measure gut inflammation using a protein called fecal calprotectin, which is released by gut cells when there’s inflammation. While research so far is mixed, it gives an idea of how colic might be linked to digestive stress in some babies.

Other studies show that infants with colic often have less diversity in their gut bacteria. This can affect digestion, gas production, and gut movement—factors that may contribute to tummy discomfort and persistent crying. Additionally, infants with colic tend to have higher levels of Enterobacteria, which can increase bloating, digestive discomfort, and gut inflammation, all of which may play a role in colic.

Although more research is needed, these findings highlight a strong connection between gut health and colic, and suggest that supporting a healthy gut could be a promising way to ease colic symptoms.

Baby colic treatments

Since the exact cause is unknown, finding a definitive treatment for colic can be challenging. While there’s no guaranteed cure, there are several techniques you can try to help calm or soothe your baby. Keep in mind that what works for one baby might not work for another, so it may take some experimenting to discover what offers relief.

Soothing techniques

• Gentle rocking: Rock your baby in a stroller, baby carrier, or rocking chair. Babywearing offers close contact and can provide additional comfort and security.

• Soothing sounds: Play calming music or white noise to help settle your baby.

• Pacifier: Sucking can be naturally comforting for many babies.

• Skin-to-skin contact: Holding your baby against your chest provides warmth, security, and a sense of calm.

Gas relief

• Tummy time on your lap: Lay your baby tummy-down across your knees and rub their back. The gentle abdominal pressure may help relieve trapped gas and ease discomfort.

• Infant massage: Massage your baby’s abdomen or bicycle their legs to release trapped gas.

• Burping: Burp your baby frequently during and after feeds to prevent gas from building up.

• Feeding positions: Try different feeding positions or bottles to reduce the amount of air your baby swallows during feeds.

For formula-fed colicky babies

Sometimes, an ingredient in your baby’s formula can cause digestive issues. According to the American Academy of Pediatrics (AAP), about 5% of colic cases are caused by a food sensitivity. If you think formula might be a factor, talk to your pediatrician about trying a hydrolyzed formula, which has proteins broken down into smaller pieces for easier digestion. Keep in mind that if you switch formulas, it can take a few weeks to notice any difference. Always check with your pediatrician before making any changes to your baby’s feeding.

For breastfed colic babies

If you’re breastfeeding or providing pumped breast milk, certain foods in your diet can pass through your milk and upset your baby’s tummy. Talk with your doctor about possible food sensitivities, such as milk or soy protein or caffeine. They may recommend an elimination diet where you remove specific foods from your diet to see if it helps. Like with formula changes, it can take about a month to notice any improvement.

The role of probiotics for colic relief

Probiotics are “good” live bacteria that help support a healthy gut. They can aid digestion, help your baby absorb nutrients, support the immune system, and promote a strong, comfortable gut that’s better able to handle stressors that might trigger digestive discomfort.

That said, not all probiotics are created equal, and different strains offer different benefits. “In exclusively breastfed infants, supplementing with this probiotic has a good chance of relieving colic symptoms,” explains Dr. Taft. Other strains, like several Bifidobacterium species and Lactobacillus reuteri DSM 17938, also show promise. While more research is needed to determine the most effective strains, probiotics offer a promising approach for supporting gut health and potentially easing colic symptoms in babies.

Colic happens and it has nothing to do with your parenting

Having a colicky baby does not mean you’re doing anything wrong. Those sleepless nights, endless attempts to soothe, and constant worry can be exhausting, leaving you feeling drained, frustrated, and at your wit’s end—and that’s completely normal. Colic is a temporary phase that your baby will outgrow. It doesn’t reflect your skills or love as a parent—it’s simply your baby’s system developing at its own pace. Taking small, consistent steps to support their comfort (and giving yourself grace along the way!) can make this challenging period a little more manageable for both of you. We’ve got your back.