What is the Stomach Flu?

The stomach flu, also referred to as gastroenteritis or a “stomach bug,” affects more than 20 million people in the United States every year. Although it is often referred to as the stomach flu, it is not caused by the same influenza respiratory virus. The stomach flu is a virus that causes inflammation or irritation of your intestines and is commonly spread through contaminated food or water or coming in contact with an infected person.

Any person can become infected with the stomach flu. However, you are at a greater risk of becoming infected if you experience shared living or dining spaces, or if you are immunocompromised. Specific risk factors include:

• Daycare or camps
• Nursing homes
• College dormitories and dining commons
• Prisons
• Military personnel
• Inpatient care facilities (psychiatric wards, residential facilities, rehabilitation centers)
• Cruise ship passengers
• Travelers to underdeveloped countries
• Being immunocompromised

Symptoms

The most common symptom of stomach flu (gastroenteritis) is watery diarrhea or loose stools. Many people also experience vomiting with stomach flu. Typical symptoms include:

• Diarrhea and vomiting
• Stomach pain
• Cramping
• Fever
• Headache
• Dehydration (signs for dehydration are thirst, dark or less frequent urination, dry skin, headache, dizziness or lightheadedness, and general weakness)

In children, it is critical to watch for signs of dehydration. Children can become dehydrated quickly, so it is important to be observant. Signs for dehydration in infants or children include dry mouth, dry skin, thirst, and drier or fewer diapers.

If your child has the stomach flu, it is best to keep them home and out of daycare or school until symptoms are gone, as it is extremely contagious. Please contact your child’s pediatrician before giving any medication to treat the stomach flu. Specifically, medications used to reduce vomiting should not be given to children under 5 and should not be given to children before consulting a doctor.

Causes

Viruses are the most common cause of the stomach flu. In adults, the norovirus tends to be the cause of stomach flu. In children, the rotavirus is the most common virus responsible for the stomach flu. These specific viruses typically infect the lining of the small intestines. Other ways you can contract the stomach virus are through bacteria, toxins, and parasites.

The loose and watery stools, which is the most common symptom of stomach flu is caused by the breaking down of gut cells, which causes malabsorption. The virus can also disrupt the reabsorption of water, thereby producing the watery loose stools. The infection can also trigger the following symptoms:

• Vomiting
• Fever and chills (a fever shows that your body is fighting an infection)
• Body aches
• Dehydration

Most people recover quickly from the stomach flu, however, there are some people who may experience complications from the stomach flu, which may be life-threatening. Infants and elderly people are more susceptible to complications from the stomach flu, and those who are immunocompromised.

Diagnosis

When to see a doctor

The stomach flu does not generally require a visit to the doctor. Most people will be able to make a full recovery from home. However, if you notice any of the following symptoms, please seek immediate medical attention:

• High fever
• Severe dehydration
• Bloody diarrhea
• Severe pain
• Symptoms that do not get better over time

Stomach flu is typically diagnosed based on descriptive or observable symptoms. But sometimes your healthcare provider may want to do further testing to rule out other issues or conditions.

Tests that might be done include:

• Stool samples. Testing stool samples assess for bacterial infections, viruses, parasites, or other toxins.
• Sigmoidoscopy. A small flexible tube with a camera on the end of it is inserted through anus and into the large intestine to check for inflammatory bowel disease. The procedure does not usually require sedation and takes about 15 minutes.

Treatment

The two most important treatment options for stomach flu include rest and proper hydration. Due to the amount of fluid that is expelled from the body during the stomach flu, hydrating with only water may not be sufficient. It is important to make sure you are replenishing your system with electrolytes. You can replenish electrolytes through various sports drinks or Pedialyte.

Antibiotics are not recommended for stomach flu as it is a viral infection. The overuse of antibiotics may lead to the development of antibiotic-resistant bacteria in your body, which may make future bacterial infections difficult to combat.

Prevention

There are several steps that can be taken to prevent contracting the stomach flu. Vaccinations do not always prevent infection, but they can reduce the risk. For children, scheduling to get the rotavirus vaccine can significantly reduce the risk of becoming infected. However, consult with your child’s pediatrician first, as not all children are able to receive the rotavirus vaccine.

There are multiple factors that lead to becoming infected with the stomach flu (gastroenteritis). The two main factors are food and water contamination and coming in contact with an infected person.

Good hand hygiene

Proper hand hygiene is crucial for stopping the spread of the stomach flu. The virus spreads through anything that has come in contact with the virus-infected feces. Prevented measures include:

• Washing your hands frequently or using hand sanitizer
• Being sure to wash your hands after using the bathroom, changing a diaper, or touching any bathroom surface
• Be intentionally mindful about good hand hygiene if you plan to come in contact with another person, or if you plan to be handling food

Being careful with food

It is important to be careful with food preparation and consumption when it comes to the stomach flu. Food and water can be contaminated with the virus, and it is possible to pass it on to other people. The goal is to keep the virus out of the food and water. Preventative measures include:

• Do not cook food or be near food in the kitchen when you are sick, or until 2 days after your last symptom
• Disinfect kitchen surfaces, especially when working with raw meat and eggs
• Keep raw meat, raw poultry, and eggs away from food that will be eaten raw
• Try to avoid eating undercooked meat, eggs, or shellfish
• Rinse fruits and vegetables before eating
• Drink only pasteurized dairy and apple juice
• Drink bottled water and avoid ice cubes when traveling in underdeveloped countries
• Clean ALL of the sick areas with disinfectant (cleaning the bathroom surfaces, washing and drying the clothes with high heat, and disinfecting all items and surfaces the sick person has touched)