Here's Why Your Kid Vomits So Much, According To Science

I'd imagine that, for the average adult, vomiting doesn't come so easily. Sure, you may have eaten some bad fish last night, but expelling that nasty trout from your system may not happen through regurgitation. The opposite seems to be true for children, though, and if you're a parent like me you've probably wondered, at one point or another, why your kid vomits so much. Turns out, there's a scientific reason for your child's predilection for spewing up yesterday's dinner — and it's not at all complicated.

First, let's break down why people vomit. Your brain receives signals from stomach-upsetting stimuli known as afferents that trigger your body to regurgitate the contents of your stomach, according to Colorado State University. As a result, your diaphragm contracts, your esophagus is forced open, your abdominal muscles squeeze, and bam: you're expelling stuff from your system.

This physiological response is the same in kids and adults. But a kid's body is much more sensitive to stomach-upsetting stimuli, according to NPR. And that's not just because their immune systems are not as fortified against stomach bugs, either. A child's body experiences afferent signals for all other kinds of physical issues, such as a fever or stubbed toe — things that wouldn't affect the average adult, NPR reported.

Pediatric gastroenterologist Katja Kovacic explained to NPR:

Anything that makes a child sick can make them vomit. There are numerous, numerous causes.

In other words, although the stomach flu is the most common reason kids may vomit, it's not the only cause. You can blame car sickness, too.

But that doesn't mean you shouldn't worry when your kid throws up. Vomiting, no matter the cause, still signals that something is wrong, and can be a traumatic experience for your child (parents, too), according to Parents. So it's important to pay attention to any accompanying symptoms — think diarrhea or stiff neck — to make sure you're not dealing with something more serious, such as rotavirus or bacterial meningitis, Parents reported.

Other signs you should watch out for, according to NPR, include: Lethargy, severe abdominal tenderness, severe pain of any kind, a distended stomach, rapid-fire vomiting, or vomiting that doesn't go away after a day. The latter two symptoms are particular causes for concern as they could lead to severe dehydration, NPR reported, which can impact your child's brain development and physical health.

Signs that your baby or child may be dehydrated include few or no tears while crying, fewer than four wet diapers in a day, or no peeing for six to eight hours, dry mouth, and weakness, among others, according to KidsHealth. If you spot any of these symptoms, call your doctor right away.

But it's not just accompanying symptoms you should observe. As gross as this may be, when your child vomits make sure to check out the expelled stomach contents themselves.

Dr. Daniel Summers, a pediatrician based in Boston, told NPR that parents should look out for "something other than the stomach contents you'd expect to find." Think blood or greenish-yellow to dark green bile, Summers said, according to NPR.

If your kid is vomiting bile, that could mean their stomach and intestines are obstructed, either from a birth defect, a meconium blockage, or volvulus, which is a twisted bowel, according to Parents. "Bile-stained vomiting is an emergency" that often require surgery, Mike Farrell, M.D., chief of staff at the Children's Hospital Medical Center of Cincinnati, told Parents.

Vomiting is still scary for children, even when the problem isn't as serious as gastrointestinal blockage (again, a stubbed toe is enough to induce throw up). So, when your kid is going through a vomiting fit, make sure they're comfortable and that you're there to soothe them as they deal with the pain.

And make sure to keep that drying cleaning tab for when they turn 18 years old.