Introduction
Stomach flu, also known as acute gastroenteritis, is an inflammation of the stomach and intestines that causes diarrhea, vomiting, and abdominal pain. It is usually caused by a viral or bacterial infection and is highly contagious. While uncomfortable, most cases of stomach flu are mild and resolve on their own within a few days.
Causes
Stomach flu is most commonly caused by viruses, such as norovirus and rotavirus. Bacterial infections, such as Salmonella and E. coli, can also cause gastroenteritis. Less commonly, parasites or toxins in food can be responsible. The infection spreads through:
- Contact with infected individuals
- Consuming contaminated food or water
- Touching contaminated surfaces and then touching the mouth
Outbreaks are common in crowded settings such as schools, daycare centers, and cruise ships.
Symptoms
Symptoms of stomach flu typically appear 12 to 48 hours after exposure and can include:
- Diarrhea (watery and non-bloody)
- Vomiting
- Nausea
- Abdominal cramps and pain
- Low-grade fever
- Headache
- Muscle aches
Symptoms usually last 1 to 3 days, but dehydration can be a concern, especially in young children, older adults, and people with weakened immune systems.
Diagnosis
Diagnosis of stomach flu is usually based on symptoms and a physical examination. In most cases, specific testing is not required. However, if symptoms are severe or prolonged, a healthcare provider may request stool tests to identify the causative organism.
Treatment Options
Treatment for stomach flu focuses on relieving symptoms and preventing dehydration:
- Drink plenty of fluids to replace lost fluids and electrolytes (oral rehydration solutions are particularly helpful)
- Rest
- Eat small, bland meals as tolerated (the BRAT diet—bananas, rice, applesauce, and toast—is often recommended)
- Avoid dairy products, sugary drinks, and fatty foods
- Over-the-counter medications such as loperamide (Imodium) can help reduce diarrhea, but should be used with caution and avoided if there is a fever or blood in the stool
Antibiotics are not effective for viral gastroenteritis and are generally not recommended unless a bacterial infection is confirmed.
Prevention
Preventing stomach flu involves good hygiene and food safety practices:
- Wash hands frequently with soap and water, especially after using the toilet and before eating or preparing food
- Clean and disinfect contaminated surfaces with bleach-based cleaners
- Avoid sharing utensils, cups, or towels with others
- Cook food thoroughly and store it properly
- Avoid consuming raw or undercooked foods
Vaccination against rotavirus is available for infants and can help prevent severe gastroenteritis.
When to Seek Medical Care
Seek medical attention if you or your child experience:
- Signs of dehydration (such as dry mouth, decreased urination, or dizziness)
- High fever
- Blood in vomit or stool
- Severe abdominal pain
- Symptoms that last longer than a few days or worsen
- Inability to keep fluids down
Takeaway
Stomach flu is a common illness that causes diarrhea and vomiting. Most people recover with supportive care, but preventing dehydration and practicing good hygiene are essential for recovery and limiting the spread of infection.