Sometime's it's hard to tell the difference between a newborn vomiting, and one that's merely spitting up. Here's a clear definition of what to look for, and how to treat both conditions.
The difference between the two is vital, since both are caused by different things. This means if you try to treat a spitting up problem with a vomiting solution, you'll get a whole heap of nothing.
Spitting up is most commonly seen in newborns 0-3 months, but a mild form of it can persist until the 10th or 12th month. It is defined as the easy flow of milk/formula out of the mouth, usually accompanied by a burp.
It is not serious and generally does not affect weight gain and growth.
Spitting up is, in fact, a mild form of reflux, having to do more with the acid balance in the stomach, than muscle contractions.
Even though spitting up is most common in newborns less than 3 months old, you may notice an increase in the amount of spit up during the 3-6 month age range.
This is may be because the muscles at the lower end of the esophagus have loosened up, allowing for more reflux.
If your infant's height, weight, and other developmental milestones are all on track, the problem should fix itself in time. In the meantime...
Newborn vomiting is when the abdominal muscles and diagphram contract vigorously while the stomach is relaxed. Most newborn vomiting is caused by viral infections, which doctor's refer to as gastroenteritis. (They'll be so impressed you know that!)
Watching your infant vomiting is heart wrenching. Vomiting isn't fun, no matter what age you are. But there's something just so wrong about seeing that tiny body convulse to throw up. This is where you step in, Mom, and take charge. And this is what you do.
There's a very good chance you're going to open up a diaper sometime in the first year and be surprised at the green watery mess splattered inside. Diarrhea is very common in babies, and although treating it is really more about enduring than prescribing, without proper managemement it can quickly get very serious...
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