There is a wicked bug going around, so I thought it was a good time to answer questions about vomiting, diarrhea, dehydrations and all that good stuff.

Q: My child has vomited five times in the last two hours. What's going on?!
A: Chances are your child has the stomach flu. Stomach flu is a general term for infections (usually viral) that cause a sudden onset of profuse vomiting and sometimes fever usually accompanied by diarrhea within 24 hours. Everyone is different, though, and some kids won't have much vomiting at all and instead will just have wicked diarrhea multiple times a day.

Q: With all this vomiting, isn't my child going to get dehydrated?
A: Not for a while. We all have some reserves and it takes quite a bit of time before dehydration sets in. Most babies older than 6 months won't get dehydrated enough to need IV fluids until they have thrown up every 45 minutes for more than six-eight hours and most school-aged kids can throw up at that rate for 12 hours or more before dehydration begins.

Q: My child keeps asking for something to drink, but as soon as she takes it she throws it up. What should I do?
A: Most of the time it makes sense to wait at least 90 minutes from the last vomiting episode before offering anything to drink. When you do offer something, it shouldn't be just plain water but something with a little sugar like Pedialyte for young children or flat Sprite or 7Up for older kids. Offering literally just sips at a time (or about a teaspoon at a time to babies) is essential. If you offer too much, even just an ounce or two, it can be enough to cause the stomach to reject it and throw up. If you can keep a trickle of fluid going down you can prevent dehydration. Once your child has gone four hours or more without vomiting, then offering slightly larger volumes makes sense. But remember, go slowly. If the stomach rejects it and vomits, the 90 minute clock starts again.

Q: How will I know if my child is dehydrated?
A: If your child is still playing between vomiting episodes, she's not dehydrated. If she's not playing but still peeing every six-eight hours, has spit in her mouth and tears when she cries, she's not dehydrated. If she's lying around like a limp rag and hasn't peed in 12 hours or her lips are cracked and her eyes look sunken, you need to hightail it to the ER.

Q: Can I give Tylenol or Motrin to lower my child's fever with this illness?
A: You can, but do so with some caution. Ibuprofen is tough on the stomach when all is well and could worsen vomiting. If you see signs of dehydration, I don't recommend Tylenol because it has to be cleared by the liver, which doesn't work as well when dehydrated and you can get toxic buildup of Tylenol, which can be very serious. If your child is vomiting a lot but not dehydrated and has a fever, Tylenol suppositories are good options. They are placed in the rectum and absorbed from there so you don't need to worry about your child throwing it up. The dose is the same and these can be found at the pharmacy behind the counter, so ask for them.

Q: How do I know if this is food poisoning?
A: It probably doesn't matter if your child isn't dehydrated. Food poisoning is managed with the same slow rehydration process as viral stomach bugs. Unless your child has dehydration, high fever for three or more days or blood in the stool, just stay the course. If a bunch of family members come down with symptoms within a few hours of each other, then food poisoning can be the culprit. Stomach bugs transferred within families typically happen sequentially; as one person is improving, the next one is starting the illness. Regardless of whether you think this is food poisoning or a virus, if your child is dehydrated or listless, you should seek care.

Q: Can I try some Imodium to slow down the diarrhea?
A: Not a good idea. Slowing down the diarrhea will just give the bug more chance to replicate and will prolong the illness. It is beneficial to vomit and poop like crazy to expel the bug.

Q: How can I prevent the rest of my family from getting this?
A: Wash your hands a lot. This is spread by fecal-oral transmission (eewww!), which means the germ is in the stool or vomit. So if you clean it up and if you don't wash your hands well, you could ingest it yourself when you eat or spread it to others.

Q: Didn't my kid get the rotavirus vaccine to prevent this?
A: Not all stomach bugs are due to rotavirus and not all rotavirus strains are covered by the vaccine. You did your child a service getting the vaccine because you will decrease the potential number of times he gets hit with a bad vomiting/diarrheal illness.

Q: How about food or milk? When do I offer those?
A: Once you have been vomit-free and tolerating clear liquids like Pedialyte for 12 hours or so you are ready to start broadening the diet again. Milk can be hard to digest. If your child is having a ton of diarrhea, he may not have as much of the enzyme to digest it well, so I would wait to reintroduce milk until your child is having fewer than eight diarrhea bowel movements a day. As for diet, there's no need to only offer bland things, but I would still avoid fried or high-fat foods as these are harder to digest. What matters most is amount: If your child eats too much too soon, regardless of what it is, he will vomit again. Go slowly and don't worry about the lack of nutrition during this time even if you have a tiny kid to start with. Once the illness is over, she will make up for lost time and regain any weight lost.

Q: He hadn't vomited in almost a day and the just threw up "everything" he ate today. Help!
A: The good news is that even though it seemed like a lot of vomit and you may well have seen pieces of undigested food from much earlier in the day in it, some of the stuff got through. You may be thinking to yourself that he really hadn't eaten much at all anyway and yet he threw up again and worry. When this occurs, go back to basics. The stomach will reject "too much" food even if it isn't much, so decrease the amount you are offering at one time and offer smaller amounts more frequently to get a trickle of food going through his system, too.

Q: How long is this going to last?!
A: The vomiting phase is usually done within a day or so with only sporadic episode of vomiting after that point. The diarrhea can last as long as 10-14 days. Fun, huh?

Q: When can my child return to school or daycare?
A: Once the vomiting phase is done, if your child's diarrhea is infrequent enough that it is manageable and not a burden to caregivers, or is down to just few times a day for an older child, returning to school or daycare is fine. Remind your child and the caregivers to wash their hands like crazy though!