Sickness and pain in the abdomen is often passed off as either stomach flu or food poisoning. However, since the symptoms are similar, people often confuse the two conditions.

Knowing the difference between the two can support an accurate diagnosis.

The Salmonella bacteria can cause food poisoning.

A viral infection that attacks the digestive system is commonly called a stomach virus.

People sometimes call the illness a 'stomach flu', although this name is misleading, as influenza attacks the respiratory system. A stomach virus can also be known as viral gastroenteritis.

Different strains of the virus exist. According to the Centers for Disease Control and Prevention (CDC), the cause in the United States is norovirus.

Food poisoning, on the other hand, describes the ingestion of contaminated food. Bacteria, viruses or less commonly parasites can enter the body and cause symptoms of gastroenteritis through food that has spoiled, been unhygienically prepared or contaminated in any other way.

The symptoms of stomach viruses and food poisoning are very similar but there can be some differences.

Stomach viruses

Abdominal discomfort is a symptom of both food poisoning and a stomach viruses, but other symptoms can help a person tell the difference.

The symptoms of a stomach virus include:

  • diarrhea that may be watery or bloody
  • a loss of appetite
  • nausea or vomiting
  • stomach cramps, muscle aches, or weakness
  • low-grade fever
  • headaches
  • light-headedness or dizziness

A stomach virus does not usually cause bloody stools. Stools that contain blood could signal a more serious infection.

These symptoms often last 3-4 days but can last for up to 14 days.

Food poisoning

Symptoms of food poisoning can occur within hours of eating. People may experience:

  • watery or bloody diarrhea
  • nausea
  • vomiting
  • stomach pain and cramping
  • a fever, chills, and body aches
  • dizziness and lightheadedness from dehydration

Sickness from food poisoning can last from .

People can usually suspect food poisoning if they ate unrefrigerated food or other individuals who consumed the same food are experiencing similar symptoms.

Salads, raw or undercooked poultry, eggs, seafood, and other dairy-based products are high-risk foods for food poisoning.

Treatment depends on the organism causing the infection.

Supportive therapy that includes increased hydration, rest, electrolyte replenishment, and medication for fever, are usually all that's needed for viral illnesses. This is because viruses do not respond to antibiotics and simply need to run their course.

If it is determined that a bacteria, like Salmonella, is causing the symptoms, an antibiotic may be prescribed. For parasites, anti-parasitic medications may be available.

There are a few steps people can take at home to aid recovery from a stomach virus or food poisoning.

  • Let the stomach settle. Try not to eat any solid foods until you feel better.
  • Suck on ice chips or take small sips of water. People should drink plenty of liquids to prevent dehydration. Avoid juices or other beverages with a lot of sugar or sweeteners that can make diarrhea worse.
  • Ease yourself back into eating. Start with bland, easy-to-digest foods, such as soda crackers, toast, and rice. Stop eating if a feeling of nausea returns.
  • Avoid certain substances until feeling better, or for a few days to a week after symptoms have resolved cleared if your case was severe. These include dairy, caffeine, alcohol, sugar, and fatty or highly seasoned foods.

People should be cautious of taking over-the-counter (OTC) medications, unless advised by a healthcare provider, as some can worsen the infection. Even anti-diarrhea medications can make the situation worse in some cases.

Gastroenteritis will typically resolve within a few days or less without medication. However, hydration is vital to a speedy recovery and prevention of complications.

People should seek medical attention if they have have any of the following symptoms:

  • bloody stool or vomit
  • unable to keep liquid down for 12-24 hours
  • dizziness or lightheadedness
  • fever above 104 °Fahrenheit (°F)
  • severe, unrelenting abdominal pain

Stomach virus

Wash fruit and veg to help keep stomach viruses at bay.

The CDC estimate that norovirus causes 19 to 21 million illnesses each year. The following preventive measures can help reduce the risk of catching a stomach virus.

There is a vaccination available in some countries that counters certain stomach viruses. The vaccine can be effective in helping to prevent severe symptoms of the virus when given to children in the first year of their life.

Food poisoning

People can help prevent food poisoning by ensuring that meats, salads, dressings, and other foods are stored at the right temperature. Do not eat food that has been left out of storage for more than 2 hours.

It is important that people wash their hands when handling any raw meat. They should also make sure to cook it thoroughly, and to avoid eating raw meat, raw eggs, or sauces made with raw eggs. During picnics or parties, food that should be refrigerated should be kept on ice.

People should also be careful when eating in restaurants or other unfamiliar environments