Colic is a crying pattern in an otherwise healthy, well-fed baby. Reflux is milk coming back up from the stomach. A baby can have one, the other, or both, and that is why the two are so easy to mix up at 9 p.m. with a baby who will not settle. The most useful clue is how your baby is doing between the hard moments: content, feeding well and gaining weight points toward colic or ordinary reflux, while pain with feeds, poor weight gain or forceful vomiting means it is time to call your pediatrician.
We work with families of babies every week, and we know how worn down a parent can feel when nothing seems to calm their little one. This guide walks you through the differences, the overlap, the warning signs and the safe things you can try today.
TL;DR
- Colic is defined by long, intense crying (more than 3 hours a day, more than 3 days a week) in a healthy baby under about 3 months, often in the evening.
- Reflux is milk or stomach contents coming back up, usually during or after feeds. It is common and usually improves as the digestive system matures.
- The two overlap, since back-arching and fussiness show up in both, so look at feeding, weight gain and mood between episodes.
- Call your pediatrician for poor feeding, forceful or green vomiting, blood, fever of 100.4°F or higher, diarrhea, breathing trouble or poor weight gain.
- Even babies with reflux sleep flat on their backs. Wedges and inclined sleepers are not the answer.
Table of Contents
- Colic and reflux side by side
- What colic is
- What reflux is
- Where they overlap
- Signs that call for a pediatrician visit
- How doctors sort it out
- What can help at home
- What about reflux medicine?
- When feeding is part of the picture
- Our perspective
- Support for you and your baby
- FAQ
- Sources
Colic and reflux side by side
This table gives the general picture. Your baby may not fit one column neatly, and that is normal.
| Colic | Reflux (GER) | |
|---|---|---|
| What it is | A pattern of excessive, hard-to-soothe crying | Stomach contents coming back up into the esophagus or mouth |
| When it happens | Often late in the day, commonly the evening hours | Mostly during or after feeds |
| Typical timing | Starts in the first month, peaks around 6 weeks, usually ends by 3 to 4 months | Common in infancy and usually improves as digestion matures |
| Baby between episodes | Content and acting normally | Often content, unless reflux is causing discomfort |
| Feeding and growth | Eating and gaining weight normally | Usually normal; poor gain is a warning sign |
| Main sign | Crying that is hard to settle | Spit-up or regurgitation |
Sources for the details in this table appear in the sections below.
What colic is
Colic is a description of behavior, not a disease. Children's Hospital of Philadelphia describes it as crying for more than 3 hours a day, more than 3 days a week, in an otherwise healthy infant younger than 3 months, with episodes that are often loud, prolonged and most common in the evening. The exact cause is not known. According to the MSD Manual, it typically emerges in the first month, peaks at about 6 weeks and resolves on its own by 3 to 4 months. The Merck Manual gives the same timeline and notes that these infants generally eat and gain weight normally.
What does it look like at home? Cleveland Clinic describes crying that follows a pattern, often late in the day, that is hard to soothe, along with clenched fists, drawn-up legs and a tense or swollen belly. Through all of it, a colicky baby keeps eating and growing.
That last part matters. Children's Hospital Colorado frames colic as recurring crying in a baby who is content and acts normally between episodes, feeds well and is not sick. If your baby has a calm, bright stretch in the morning and then falls apart at dinnertime, that rhythm is a classic colic clue.
What reflux is
Reflux simply means milk coming back up from the stomach. It is common in babies, and a UK health library entry notes that it usually improves as the digestive system matures. Doctors call this gastroesophageal reflux, or GER. Babies have a small stomach, a lot of liquid in their diet and a muscle at the top of the stomach that is still developing, so a certain amount of spit-up is part of being a baby.
Reflux becomes a concern when it comes with other symptoms or lasts beyond infancy. At that point it may be called gastroesophageal reflux disease, or GERD. The 2009 NASPGHAN-ESPGHAN guidelines state that no single symptom or group of symptoms reliably diagnoses GERD in infants and toddlers, which is why your pediatrician looks at the whole picture and watches for warning signs.
Reflux you can see and reflux you cannot
Some babies spit up visibly and are perfectly happy. Others have what many parents call "silent reflux," where milk comes up and is swallowed again without obvious spit-up. That term is not a formal diagnosis, but the idea is real for many families: a baby who gulps, coughs or seems uncomfortable with feeds without much mess. If this sounds like your baby, mention it to your pediatrician rather than guessing.
Where they overlap
Both can bring fussiness and back-arching, and both can show up in a baby who seems unhappy. The UK health library entry above describes colic as a prolonged, intense crying phase in a healthy infant, with reflux symptoms occurring mainly during or after feeds. Many colicky babies also have some reflux, and that is part of why parents get confused.
Three questions help sort things out:
- When does the distress happen? Crying clustered in the evening, regardless of feeds, leans toward colic. Distress during or right after feeds leans toward reflux.
- How is your baby between episodes? A baby who is happy, alert and relaxed in between fits the colic picture.
- How are feeding and weight? Normal appetite and steady weight gain are reassuring. Refusing feeds, choking, or slow gain is something to bring to your pediatrician soon.
Children's Hospital Colorado makes a useful point here: gas and spit-up are often blamed for crying, but the more helpful question is whether the baby is happy between episodes and well nourished.
What about gas?
Gas is the third suspect in a fussy baby. A colicky baby often burps or passes gas, but Johns Hopkins Medicine explains that this is usually because crying makes babies swallow air. Available evidence does not show that gas causes colic. Gas itself tends to look like fussiness, a full belly and a lot of burping or flatulence. If your baby is passing gas and then settles, it was probably gas. If hours of crying continue despite that, colic is more likely.
Signs that call for a pediatrician visit
Most babies with colic or ordinary reflux are healthy. Still, some symptoms point away from either and deserve a prompt call. Johns Hopkins advises contacting your baby's healthcare provider for poor feeding, vomiting, diarrhea, abnormal breathing, unusual sleepiness, a fever of 100.4°F (38°C) or higher, or excessive crying.
For reflux in particular, the NASPGHAN guidance lists these warning signs:
- Vomit that is green or yellow-green (bilious) or persistently forceful
- Blood in the vomit or stool (GI bleeding)
- Failure to thrive, meaning poor weight gain
Can colic cause diarrhea?
No. Colic is not expected to cause diarrhea. Johns Hopkins advises calling your provider when crying comes with loose stool, since it can also happen with a milk allergy or intolerance. The Merck Manual's consumer guide lists diarrhea, vomiting, blood or mucus in stool, fever, lethargy, breathing difficulty and poor weight gain as signs that suggest illness or another cause, and they warrant prompt medical evaluation. Trust your instincts. If something feels off, call.
How doctors sort it out
There is usually no scan or test involved. For babies with uncomplicated recurrent spit-up, the NASPGHAN guidelines say a thorough history and physical exam, with attention to warning signs, are generally enough to establish reflux. For crying, the Merck Manual's professional guidance explains that the key task is separating a repetitive but reassuring crying pattern from treatable problems such as reflux, allergy, infection, constipation or obstruction.
To make that visit count, it helps to bring notes for a few days:
- When the crying starts and how long it lasts
- How feeds go: position, duration, coughing, gulping, pulling off
- How often your baby spits up and how much
- Wet diapers and stools
- What you tried and what helped
If feeding itself seems to be the sticking point, our post on what to do after two weeks of infant feeding difficulties can help you decide on next steps.
What can help at home
The goal is comfort for your baby and rest for you. Nothing here is a cure, and colic ends on its own, but small changes can make the hours easier.
For reflux
- Hold your baby upright during feeds and for a short time afterward. The UK health library entry suggests this may help babies with reflux disease.
- Pace the feed. Take breaks to burp, and watch for signs of fullness.
- Check the latch or bottle flow. A baby gulping or swallowing a lot of air can feel more uncomfortable. Breastfeeding families may find our guide on easing reflux at the breast helpful.
- Ask about formula options. For formula-fed infants with symptoms suggestive of reflux disease, the NASPGHAN summary says evidence supports a 2 to 4 week trial of an extensively hydrolyzed protein formula. Your pediatrician decides whether that is right for your baby. A doctor may also suggest thickened formula.
For healthy, thriving babies whose symptoms are likely normal reflux, the same guidelines note that parent education, guidance and support are usually enough.
For colic
Because colic fades with time, the aim is to get through the evenings safely and calmly. Many parents rely on holding, swaddling for awake soothing (never for unsupervised sleep), gentle motion, a quiet room, white noise and taking turns with another adult. If you feel overwhelmed, put your baby down safely on their back in the crib, step away for a few minutes and breathe. Crying is hard on parents, and clinicians are encouraged to show compassion because a colicky baby is genuinely stressful, as the MSD Manual notes.
Safe sleep comes first
It is tempting to prop a refluxy baby on a slope, but the American Academy of Pediatrics recommends that even babies with GERD sleep flat on their backs, not on their stomachs or sides. The UK health library entry adds that the mattress should be firm and flat, with no pillows or wedges. If you are worried about nighttime reflux, talk with your pediatrician instead of changing the sleep surface.
What about reflux medicine?
Parents often ask whether a reflux medicine will calm a crying baby. The NASPGHAN guidelines say there is no evidence to support a trial of medication as a way to diagnose GERD in infants and young children, and that no proton pump inhibitor is approved for infants younger than 1 year. They also say the potential benefits of prokinetic agents are outweighed by side effects, and routine use of metoclopramide is not supported. A Cleveland-style summary from a parent-focused article is not needed here: the message is simple. Do not start or change any medicine for your baby without your pediatrician's guidance.
When feeding is part of the picture
Sometimes what looks like colic or reflux is partly a feeding challenge: a shallow latch, a fast bottle flow, difficulty coordinating suck, swallow and breathe, or tension in the neck and jaw. These are things a feeding or lactation specialist looks at closely. Our posts on feeding red flags and on breastfeeding with torticollis cover signs that deserve a closer look.
A specialist does not replace your pediatrician. Medical causes of vomiting, poor weight gain or blood in stool come first. Once those are addressed or ruled out, feeding support can make feeds calmer for both of you.
Our perspective
We meet many parents who arrive tired and a little afraid that they are missing something. Our first message is almost always the same: you are not doing it wrong, and your concern is worth listening to.
At Thriving Joy, we look at the whole feeding picture. When a baby is fussy at the breast or bottle, we consider positioning, latch, flow, comfort, and the family's routine, and we look for the root cause instead of a quick fix. Our approach is holistic and family-centered, and it combines pediatric healthcare experience with the real-life understanding of what it is like to parent a baby.
We always encourage families to start with their pediatrician to rule out medical causes. From there, our feeding therapy and lactation counseling are designed to give you practical, individualized support, so mealtimes feel calmer and you feel more confident. Many parents tell us that simply having a plan makes the long evenings easier.
We can also meet you where you are, whether that is our office, your home, daycare or preschool.
Thriving Joy
Support for you and your baby
If feeds are stressful, your baby seems uncomfortable while eating, or you simply want a trained set of eyes on how things are going, we can help. We offer lactation counseling for prenatal education and postpartum breastfeeding support, and feeding therapy for infants and children in Pasco and Hillsborough Counties. We accept private pay, major health insurance plans and scholarships. You can also explore our parent coaching and classes for ongoing guidance.
FAQ
How can I tell the difference between colic and reflux?
Look at timing and mood. Colic is long crying, often in the evening, in a baby who is content between episodes and feeding and growing well. Reflux shows up mainly during or after feeds as spit-up or discomfort. Your pediatrician can confirm with a history and exam.
Can a baby have colic and reflux at the same time?
Yes. Many babies with colic also have some reflux, and the symptoms overlap. Your pediatrician can help you work out which one is driving the fussiness and whether any warning signs are present.
What is the best sleeping position for a baby with colic or reflux?
On the back, on a firm, flat sleep surface, every time. The AAP says this applies to babies with GERD too. Avoid wedges, pillows and inclined positions for sleep.
How can I tell the difference between gas and colic?
Gas tends to bring fussiness, a full belly and burping or flatulence, and the baby often settles after passing it. Colic involves hours of crying, often in the evening, in an otherwise well baby. Burping and gas during colic usually come from swallowed air while crying.
When should I call the doctor about my fussy baby?
Call for poor feeding, vomiting, diarrhea, blood in stool, abnormal breathing, unusual sleepiness, poor weight gain, or a fever of 100.4°F (38°C) or higher. Call too when the crying seems different from usual or you are worried.
Sources
- Colic and Gas, Children's Hospital of Philadelphia
- Colic, MSD Manual Professional Edition
- Colic, Merck Manual Professional Edition
- Colic, Merck Manual Consumer Version
- Colic Symptoms, Causes and Solutions, Cleveland Clinic
- Crying Baby Before 3 Months, Children's Hospital Colorado
- Colic, Johns Hopkins Medicine
- Reflux and Colic, Doctify health library
- Gastroesophageal Reflux Clinical Practice Guidelines, NASPGHAN
- A Parent's Guide to Safe Sleep, American Academy of Pediatrics