Stomach Flu

The stomach flu is a viral infection of the stomach and intestines. Stomach flu symptoms include vomiting, watery diarrhea, and cramps that usually clear in 1 to 3 days. Despite the name, it is not related to the flu.

What Is It

Doctors call it viral gastroenteritis. It spreads easily through contaminated hands, surfaces, food, and close contact, and often moves through a household, school, or daycare. Cases peak in the Chicago area in winter and early spring.

Symptoms

Sudden nausea and vomiting
Watery diarrhea
Stomach cramps
A low fever and chills
Headache and body aches

Vomiting usually eases within a day, while diarrhea can last a few days longer.

Not sure it’s the stomach flu? Food poisoning tends to hit several people who shared a meal at the same time. Steady pain that moves to the lower right side may be appendicitis.

Treatment

At your visit: A provider checks for dehydration, the biggest risk with the stomach flu, especially in young children and older adults. Medicine for vomiting can help you keep fluids down, and IV fluids may be used when needed. Antibiotics do not help because it is a virus.

At home:

Take small, frequent sips of an oral rehydration drink
Try ice chips or frozen pops if fluids will not stay down
Eat bland foods once vomiting stops
Wash hands with soap and water, since hand sanitizer does not kill many stomach viruses

Most people recover in 1 to 3 days, but you can stay contagious for a few days after you feel better.

When to Get Care for the Stomach Flu

Watch at Home

Vomiting or diarrhea for less than a day
Able to keep small sips down
Urinating normally

Come to Urgent Care Today

Unable to keep fluids down for more than 6 to 8 hours
Diarrhea lasting more than 3 days
Signs of mild dehydration, like dark urine or a dry mouth
A child with fewer wet diapers or bathroom trips
A fever above 102 degrees

Go to the Emergency Department

Blood in vomit or stool
Signs of severe dehydration, like no urine for 8 hours, confusion, or fainting
Severe belly pain that is steady and getting worse
Green vomit
A baby under 3 months with vomiting or fever

FAQ

How long does the stomach flu last?

The stomach flu usually lasts 1 to 3 days. Vomiting tends to stop first, and diarrhea can linger a few days longer.

How long is the stomach flu contagious?

The stomach flu is most contagious while you are sick and for the first few days after you feel better. Some stomach viruses can spread for up to 2 weeks, so keep washing your hands.

What should I eat with the stomach flu?

With the stomach flu, focus on fluids first, using small sips of an oral rehydration drink. Once vomiting stops, try bland foods like toast, rice, crackers, and bananas.

Is the stomach flu the same as the flu?

No, the stomach flu is not the same as the flu. The stomach flu is a virus that infects the gut, while the flu is a respiratory virus. The flu shot does not prevent the stomach flu.

When should I go to urgent care for the stomach flu?

Go to urgent care for the stomach flu if you cannot keep fluids down, have signs of dehydration, or have diarrhea for more than 3 days. At Vitality Urgent Care, a provider can check for dehydration, and IV fluids are available when needed.

How do I stop the stomach flu from spreading?

Stop the stomach flu from spreading by washing hands with soap and water, cleaning surfaces with a bleach based cleaner, and not cooking for others until 2 days after symptoms end.

Last reviewed October 2026