Why does baby spit up after feeding?

Babies spitting up after feeding is very common and usually doesn't need worry. There can be a few reasons.

In babies, the muscle between the food tube and stomach (lower esophageal sphincter) isn't fully mature yet. This is why stomach contents can easily come back up. This is often called "reflux" or colloquially "milk spit."

If your baby seems happy, energetic, and is gaining weight well, this is usually a normal process and will pass with time.

Babies spit up when they burp out extra air or spit out extra milk if they've eaten too much. Swallowing air during feeding or eating too fast or too much can trigger spitting up.

When to see a doctor:

• If your baby's spit-up contains bile (greenish-yellow) or blood
• If spitting up is projectile and severe
• If your baby's weight gain has stopped or slowed
• If there's fussiness, refusing to feed, or constant crying
• If your baby is under 3 months and spitting up is getting worse

You didn't mention your baby's age — this situation is very different between a few weeks and a few months old. If your baby is in their first 3 months and spitting up is getting worse, there might be a condition called pyloric stenosis; this definitely needs a pediatrician's evaluation.

In short, if your baby seems happy and is gaining weight well, this is probably a normal phase. But if any sign is making you worry, don't hesitate to check with your pediatrician.