What is the 24-hour flu? You may have heard of the “24-hour flu” or “stomach flu,” a short-lasting illness characterized by vomiting and diarrhea. But what exactly is the 24-hour flu? The name “24-hour flu” is actually a misnomer. The illness isn’t the flu at all. The flu is a respiratory illness that’s caused by the influenza virus. Common symptoms of the flu include fever, cough, body aches, and fatigue. The 24-hour flu is actually a condition called gastroenteritis. Gastroenteritis is an inflammation of the lining of the stomach and intestines, which leads to symptoms such as vomiting and diarrhea. Although gastroenteritis can be caused by viral, bacterial, or parasitic infections, viral gastroenteritis is typically responsible for many cases of 24-hour flu. Despite the “24-hour” moniker, viral gastroenteritis symptoms can last between 24 and 72 hours. Read on to learn more about the 24-hour flu, including symptoms, home remedies, and when to see a doctor.

What are the symptoms? The symptoms of 24-hour flu typically appear one to three days after you’ve been infected and can include: diarrhea

nausea or vomiting

abdominal cramps or pain

loss of appetite

low-grade fever

body aches and pains

headache

feeling tired or fatigued Most people with 24-hour flu notice that their symptoms begin to disappear within a few days.

How does the 24-hour flu spread? The 24-hour flu is very contagious, meaning that it can spread easily from person-to-person. You can become infected in the following ways: Having close contact with a person who has the infection.

Coming into contact with a surface or object that’s been contaminated. Examples include things like doorknobs, faucets, or eating utensils.

Consuming contaminated food or water. If you develop symptoms, wash your hands frequently, especially after using the bathroom and before handling food. Since the illness is very contagious, plan to stay home for at least 48 hours after your symptoms have passed.

What causes the 24-hour flu? The 24-hour flu is often caused by one of two viruses: norovirus and rotavirus. Both viruses are shed in the stool of an infected person, meaning that you can become infected if you ingest tiny particles of stool from an infected person. This can occur when proper hygiene or food handling practices aren’t carried out. Symptoms typically occur one or two days after infection and can last for a few days. Viruses can’t be treated with medication. Since the infection is caused by a virus, treatment focuses on easing symptoms until you get better. 24-hour flu vs. food poisoning Although you can get the 24-hour flu from contaminated food and water, the condition is different from food poisoning. Food poisoning is caused by contamination of food or water, and can be caused by bacteria, viruses, or parasites. Often, the symptoms of food poisoning come on more quickly than the symptoms of 24-hour flu — usually within hours of ingesting contaminated food or water. Typically, the symptoms of food poisoning last a few days. Some types of food poisoning may last longer. Additionally, since various types of bacteria can cause food poisoning, antibiotics may be necessary to treat the infection.

How to treat the 24-hour flu at home If you’ve come down with the 24-hour flu, you can do the following things at home to help ease your symptoms: Drink plenty of fluids to replace the fluids lost from diarrhea and vomiting. Examples include water, diluted juices, and broth. Electrolyte solutions, such as Pedialyte or diluted sports drinks (Gatorade, Powerade), can also be used.

Eat plain or bland foods that are less likely to irritate your stomach. Examples include things like bread, rice, and crackers.

Rest up. Getting plenty of rest can help your body fight the illness.

Use an over-the-counter (OTC) anti-vomiting or anti-diarrheal medication. Be sure to talk to your doctor or pharmacist about which types may be appropriate for your condition.

Take an OTC pain reliever such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) to ease any body aches and pains.

When to seek help Seek medical attention if you experience any of the following while you’re ill with the 24-hour flu: You have symptoms of severe dehydration, which can include dizziness, dark urine, or passing very low quantities of urine.

You have bloody diarrhea or vomit.

You’re unable to keep any fluids down for 24 hours due to vomiting.

Your fever is over 104°F (40°C).

Your symptoms don’t begin to improve after a few days.

You have an underlying condition such as inflammatory bowel disease or kidney disease.

Your symptoms begin after you’ve traveled internationally, particularly to an area with poor sanitation.