Babies don’t have big tummies. At birth, a baby’s tummy is about the size of a cherry. After 3 days, it has made it to walnut dimensions. What this means is that it really cannot hold very much. In fact, until she is about 4 months old, your baby’s stomach can hold only small amounts of milk at a time. This is one of the main reasons why you have to feed her so often early on. Too much milk during feedings can cause your baby to spit up or be fussy because she feels overly full. Spit-up is generally milk coming straight back up due to an overflow of that tiny tummy, or air bubbles swallowed during feeding.

Many babies spit up regularly. It is not painful, and she might not even realize she has done it. If your baby is healthy and gaining weight, you really do not need to worry about it, as it is just part of the development process.

If spitting up is making your baby uncomfortable and gets more forceful with more volume than usual, she might be vomiting. Although this can be alarming, an occasional vomiting episode is usually not a reason to be concerned. Contact your health care professional if your baby's spit-up:

• increases in volume or force;
• causes choking episodes or respiratory difficulty (wheezing or coughing);
• leads to other issues (discomfort, fussiness, poor weight gain, or weight loss);
• is accompanied by a fever, diarrhea, bloody mucus in the vomit, or a bloated abdomen;
• is green or yellow;
• is frequently projectile.

Because babies younger than 1 year of age are at greater risk of dehydration, consult your health care professional immediately if you think your baby might be dehydrated. It is important that you replace the fluids your baby is losing with small, frequent feedings while she is ill. Your child’s doctor may recommend an oral rehydration solution such as Pedialyte^®. Please note that this information is not meant to replace the advice of your baby’s health care professional who we recommend you contact if you are concerned, or before making changes to your baby’s diet.