Stomach Viruses
I think stomach virus symptoms are more dreaded than a lot of other types of symptoms, sometimes because as individuals we may be triggered to feelings of nausea when we see others vomiting, and sometimes because the task of trying to just “keep your child well hydrated as the virus runs its course” (as a lot of doctors will say) seems daunting when the whole problem with a stomach virus is that nothing stays down, or that anything that goes in comes right out the other side. I can’t do anything about those of us that get queasy at the thought or sight of another vomiting person, but hopefully, this article will help make the second obstacle easier to conquer.
Vomiting can be caused by other illnesses, also, but this article will address vomiting and diarrhea as part of the common “stomach bug.” The common “stomach bug” is a virus that manifests with nausea, vomiting, fever, abdominal pain, or diarrhea. An individual patient may have some or all of these symptoms. As with any other virus, the illness will run its course, and the body’s immune system will take care of the infection, so it is true that all you have to do is to “keep your child well hydrated until the virus runs its course.” It’s how to do this that can sometimes be tricky. Understanding what the virus does to the body can help a little in figuring out how to succeed.
When you catch a stomach virus, usually the virus causes your stomach to empty more slowly. Having stuff in your stomach (because it’s not emptying) can cause a feeling of nausea and can increase the chances of vomiting. The foods that normally take longer to empty anyway, even when the stomach isn’t sick, are foods that are higher in fat and protein. Starchy foods are partially digested by just the saliva in the mouth, so the stomach doesn’t have to do much to them. Clear liquids require the least amount of stomach effort to digest, so they are what usually empty the most quickly. Large volumes also take longer to empty, because there is more of it to go through. Based on that knowledge, that is why it’s recommended to take small frequent volumes of clear liquids. Clear liquids (for example, pedialyte) don’t require any digestion, and if it’s just a teaspoon or two (5-10 mL) oftentimes it can make its way through the stomach into the small intestine without coming back up. Even broth has a little bit of fat or protein, and formula/milk also. Breast milk is the only nonclear fluid that is an acceptable substitute, but it should only be given also in small quantities, just more frequently. Large volumes of any fluids including clears will not empty quickly from a stomach that doesn’t want to work well, and the longer you have the stomach full of stuff, the more likely that stuff is going to go right back up. I usually tell older kids to take 2-3 sips of pedialyte or diluted sports drink every 10-15 minutes. Younger kids may need to have their parents use a syringe to squirt 5-10 ml into their mouths every 10-15 minutes because they don’t understand that they need that fluid to stay hydrated, and all they understand is that they don’t feel good and would rather not be bothered by drinking. On the other hand, they may feel really thirsty and try to guzzle down 4 ounces of something, which will just come right back up. Slow and steady does the trick … Don’t even think about food until after the body has shown that it can keep down clear fluids (or breastmilk) for about half a day, and once you start solids, start with easy bland starchy stuff like bread or crackers and gradually increase the amount of food at a time, even if your child seems to be feeling fine again.
Why do I keep talking about Pedialyte? Pedialyte (or any store brand generic) is a perfectly balanced mix of water, glucose (a sugar source), and electrolytes. Plain water doesn’t have any sugar source or electrolytes. Clear juices (apple juice, pear juice, etc) and undiluted sports drinks have too much sugar. They may irritate the already upset stomach and definitely cause more water to enter the stool contents and aggravate diarrhea, the other end of the spectrum of stomach bug symptoms. Even if you don’t eat any food, your body can sustain itself as long as it has fluid and glucose (a source of energy for your cells) and electrolytes (which allow the mechanisms of your body to continue to work). Also, the reabsorption of water in the small intestine is boosted by having glucose and electrolytes present in the intestinal contents, so that’s why pedialyte is better than plain water … if the same amount is ingested, your body will actually absorb more of the pedialyte than the plain water.
Usually, the vomiting part of a stomach virus lasts up to 48 hours. The diarrhea may start as soon as the vomiting starts, or it may take another 24 hours or so. It is more concerning, in fact, that something else may be going on if vomiting persists 48-72 hours without diarrhea also developing. Diarrhea is what happens when the virus makes its way to the intestines and causes the intestines to pass their contents along more quickly, thus resulting in less fluid being reabsorbed, or actually triggers the intestines to secrete more fluid into the intestinal contents. You can’t change what the virus does to the intestinal cells, but you can count on the intestinal cells to still try to work the way they are made to, which is to try to balance the concentration of water, glucose, and electrolytes inside the intestines and inside the bloodstream. They do this by selectively absorbing water, glucose, and electrolytes from the intestinal contents, especially when they are in the perfect ratio, or by secreting fluid into the intestinal contents. Too much sugar in the intestinal contents, through basic rules of chemistry, draw more water into the intestinal contents to try to even out the concentration inside and outside the intestines, and the more water in the intestinal contents, the more diarrhea. Typically foods/drinks that are high in sugar are sodas, juices, and undiluted sports drinks, along with fruits. These are therefore things that you want to avoid when you have diarrhea. Now, intestinal cells need protein to recover, so eating small amounts of lean protein should eventually help things recover faster. Again, not something that needs to be done in the first 3-4 days when the symptoms are the most severe, but once you’re at the point of “ok, how long is this going to go on?” Some studies have also shown that probiotics may help re-establish the balance of good bacteria that normally live in the intestines, and therefore may shorten the duration of stomach viruses, but ask your pediatrician about appropriate brands and doses. Sometimes prolonged diarrhea can trigger a temporary lactose intolerance, so if the diarrhea as been going on a while, you may want to avoid dairy milk for a few weeks.
So in the first 24-48 hours of a stomach bug, small frequent sips of clear fluids (breastfed babies can continue to nurse briefly and frequently). Once nausea resolves, can start with small amounts of starchy foods and advance to also include small amounts of lean protein. Consider probiotics. Advance diet slowly as tolerated. The normal course is that vomiting has resolved by 72 hours, diarrhea may take up to 7-10 days to completely resolve. Fever, if there is any, is within the first 72 hours also. Anything outside of the normal range of expected time periods increases the possibility that the vomiting is from something else, so should be evaluated more closely.