Published 2025-12-23 · Health & Safety · 3 min read

Colic vs. Reflux: How to Tell the Difference in Your Fussy Baby

An inconsolably crying baby is one of the most stressful, self-doubt-inducing experiences of new parenthood. When soothing doesn't work, it's natural to hunt for a reason — and two names come up again and again: colic and reflux. Their symptoms overlap enough to be genuinely confusing, but they have different causes, different patterns, and different things that help. Knowing which one you're likely dealing with helps you stop guessing and start soothing.

What Is Colic?

Colic isn't a disease — it's a description of a pattern of crying in an otherwise healthy, well-fed, growing baby. Pediatricians often use the "Rule of Threes":

• Crying for more than 3 hours a day
• On more than 3 days a week
• For more than 3 weeks

The crying is intense, often clusters in the late afternoon or evening (see our tips for the witching hour), and can seem to come out of nowhere. A colicky baby may pull their legs up, clench their fists, and go red in the face. The exact cause is unknown, and — importantly — it is not caused by anything you did. Much of this intense evening crying is now understood as part of the normal Period of PURPLE Crying, a developmental phase all babies pass through to different degrees.

Key signs of colic:

• Crying is intense and fairly predictable, often at the same time each day.
• Baby is otherwise healthy, feeding, and gaining weight well.
• Soothing attempts frequently fail — and that's not your fault.
• Usually peaks around 6 weeks and eases by 3–4 months.

What Is Reflux (GER)?

Gastroesophageal reflux (GER) is when stomach contents flow back up into the esophagus. It's extremely common in babies because the ring of muscle at the top of the stomach is still immature, and because babies spend so much time lying down drinking large volumes relative to their size. Most reflux is a "laundry problem, not a medical problem" — the baby spits up but is otherwise happy and growing.

Reflux becomes a bigger deal (sometimes called GERD) when it causes pain, feeding trouble, or poor weight gain. There's also silent reflux, where the contents come up but are swallowed back down, so you see the discomfort without the visible spit-up — our guide to silent reflux signs covers that pattern in detail.

Key signs of reflux:

• Frequent spitting up or "wet burps."
• Crying and arching the back during or right after feeds.
• Fussiness when laid flat; more settled when upright.
• Poor feeding, pulling off, or refusing to eat.
• In more severe cases: poor weight gain, chronic cough, or breathing issues.

Colic vs. Reflux: The Main Differences

The honest truth: many babies have a bit of both, and telling them apart isn't always clean. What helps most is watching the timing. If the worst crying clusters at the same time each evening, colic/PURPLE crying is likely. If it reliably shows up mid-feed or right after, and comes with spit-up or arching, reflux is the better bet.

Track the timeline. Logging feeds, crying spells, and spit-up in a free MyBabyTracker account turns a blur of hard days into a clear pattern — and gives your pediatrician exactly the timeline they need to help. If a cry has you stumped, the built-in cry analyzer (free) can offer a best-guess interpretation to point you in the right direction.

What You Can Do

For colic:

• Try the "5 S's": Swaddling, Side/stomach position (only while you're holding them), Shushing, Swinging, and Sucking (a pacifier or clean finger).
• A warm bath, motion (a walk or a car ride), or gentle tummy/leg-bicycle massage.
• Ask your pediatrician about probiotic drops, which some evidence supports for breastfed colicky babies.
• Protect your own limits — put the baby down safely and step away for a few minutes if you feel overwhelmed. This is safe and smart.

For reflux:

• Keep baby upright for 20–30 minutes after every feed.
• Offer smaller, more frequent feeds so the stomach isn't overfull.
• Burp your baby more often, including a pause mid-feed.
• Avoid tight diapers and waistbands that press on the belly.
• For formula-fed babies, your doctor may suggest a thickened (AR) or hypoallergenic formula. If symptoms point to a milk allergy, read our guide to cow's milk protein allergy (CMPA).
• Never prop the crib or add pillows — safe sleep still means flat and on the back, even with reflux.

One thing to rule out for either: overtiredness. An overtired baby can cry just as inconsolably as a colicky one, and the fix is completely different. Check that naps are landing at the right times with our free nap calculator.

Frequently Asked Questions

Does colic mean my baby is in pain? A colicky baby looks like they're in pain, but colic itself isn't thought to be a painful condition. That's part of why the "PURPLE crying" framing is reassuring — it's a phase, not an injury.

Will changing my diet help if I'm breastfeeding? Sometimes, but not usually. Blanket diet changes rarely help typical colic. If you suspect a milk protein allergy (blood or mucus in stool, eczema, reflux-like symptoms together), talk to your pediatrician before eliminating foods.

When does it end? Colic typically fades by 3–4 months. Reflux usually improves as your baby spends more time upright, starts solids, and the stomach valve matures — often much better by 6–12 months.

When to Talk to Your Pediatrician

See your pediatrician promptly if your baby has projectile vomiting, poor weight gain, blood in the spit-up or stool, refuses feeds, has fewer wet diapers, a fever, or seems to be in genuine, escalating pain. Also reach out if the crying is pushing you past your limit — support for exhausted, overwhelmed parents is part of your baby's care too, and asking for it is the responsible move.

This article is for informational purposes only and is not a substitute for professional medical advice.