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Emergency Department Discharge Instructions

Gastroenteritis (stomach flu)

Emergency Care Discharge Instructions

Instruction summary

Gastroenteritis (often called “stomach flu”) is an infection of the gut. This can be caused by a bacteria or a parasite, but is most commonly caused by a virus. Antibiotics do not work on viruses (they only work on bacteria), so there is no point in taking an antibiotic for most cases of gastroenteritis.

The most important thing for you to do is to stay hydrated. If you or your child is vomiting, do not try to drink lots of fluid immediately after vomiting. Wait a few hours after the vomiting has stopped and then try to drink one tablespoon of fluid. If this causes more vomiting, wait a few more hours after the vomiting has stopped and then try again. If it doesn’t cause more vomiting, continue hydrating yourself one tablespoon at a time every 10 minutes until you are able to tolerate more.

The fluid can be water, Pedialyte, Gastolyte or flat ginger-ale. If you can keep down the fluids for a few hours without vomiting, you can try eating food. Choose foods that are very plain, such as the B.R.A.T. diet: Bananas, Rice, Apple sauce and Toast. You can also eat plain chicken (without the skin) and clear soups and crackers.

The vomiting usually lasts 12-24 hours, and is followed by diarrhea for several days. If the diarrhea is very bad, you can take an over-the-counter anti-diarrheal medication for it. It is generally thought to be a good idea to wait at least one to two days after the diarrhea starts before taking any anti-diarrheal medication.

Reasons to return to the ER
  1. Dehydration. Signs of dehydration:
    • Producing fewer wet diapers or peeing less
    • A dry mouth with no visible spit bubbles
    • No tears made when crying
  1. Lethargy. Lethargy is an extreme form of tiredness when a child is only minimally responsive. An example of a lethargic child is a child who is lying still and does not make eye contact with you when you speak to them.

  2. High fever (≥40.0°C / 104.0°F)

  3. Blood in the diarrhea

  4. If the abdominal pain moves to one side of the abdomen