The stomach flu or stomach bug, also known as gastroenteritis, is the inflammation of your gastrointestinal tract—the stomach and the intestine. 

Influenza, commonly known as the "flu" is an extremely contagious respiratory illness caused by viruses, mainly influenza A or B viruses. Viruses are microorganisms that are smaller in size than bacteria that cannot reproduce by themselves outside a host’s body.

While the stomach flu affects the stomach, influenza only affects the respiratory system (nose, throat, and lungs). 

Influenza appears most frequently in winter and early spring. The influenza virus attacks the body by spreading through the upper and/or lower respiratory tract. 

How are Stomach Flu and Influenza Caused?

Causes of Stomach Flu

The most common cause of gastroenteritis (Stomach flu) is a virus. The main types of the virus are rotavirus and norovirus. Rotavirus is the most common cause of diarrhea in infants and young children. Norovirus is the most common cause of serious gastroenteritis and also foodborne disease in adults as well as children. 

The bacterial stomach flu is not common however, bacteria such as E. coli and Salmonella can also trigger stomach flu and are usually spread by undercooked poultry, eggs, or poultry juices. Salmonella can also be spread through pet reptiles or live poultry.

Causes of Influenza

There are two main types of flu or influenza viruses that affect humans: Type A, and Type B. Humans contract ‘type A’ flu from animals.

‘Type B’ flu is seasonal and is typically less severe than type A and causes milder symptoms. Type B can only be transmitted from humans to humans.

The infection caused by stomach flu and influenza both differs in their symptoms. Let’s understand how they are different.

Symptoms of gastroenteritis may include:

  • Diarrhea (watery stools)

  • Nausea, vomiting, and abdominal pain

  • Fever with chills/ fever without chills

  • Lack of energy

  • Dehydration (loss of excessive water from your body) may also occur

You may initially have chills, fever, and nausea and this can progress to vomiting, diarrhea, severe headaches and/or body aches. Unfortunately, there is no cure for bacterial or viral stomach flu. The disease has to run its course and medications can only provide you relief from the symptoms. 

Symptoms of influenza include:

  • A high temperature (103 F to 104 F) that lasts 3–4 days

  • Stuffy or runny nose 

  • Cold sweats and shivers

  • Headaches and body aches that may be severe

  • Fatigue  

How do Stomach Flu and Influenza spread? 

  • The spread of stomach flu can occur through: 

    • Contact with someone who has the virus

    • Contaminated food or water

    • Unwashed hands after going to the bathroom or changing your child’s diaper

  • The influenza virus spreads when people with influenza cough, sneeze, or talk, sending droplets with the virus into the air and potentially into the mouths or noses of people who are nearby.

What is the treatment of Stomach Flu and Influenza?

Stomach flu treatments

The cure for stomach flu is not present and antibiotics cannot treat viral stomach flu. Antibiotics are medicines that help in treating infection by killing or inactivating the bacteria in your body. Therefore, your doctor will aim for symptomatic relief. 

Your doctor may prescribe painkillers and medications to reduce the severity of symptoms like antipyretics (to reduce fever), antidiarrhoeals (to treat diarrhea), antiemetics (to relieve the feeling of nausea), etc. 

Influenza Treatment

  • In some cases, influenza A symptoms can clear on their own with ample rest and fluid intake.

  • In cases of influenza B, your doctor may prescribe antiviral medication to fight the infection. Over-the-counter (OTC) medication can also ease flu symptoms. You should drink more water and stay hydrated. This can help loosen mucus in your chest and strengthen your immune system.

The best way to avoid falling sick with stomach flu and influenza are to maintain distance from people who are infected or down with a cold or stomach bug. These infections are most commonly seen in children aged between 5 and 15 years. The weather also affects your risk of being infected with germs that cause either of these diseases. If you or your near and dear ones experience symptoms of stomach flu or influenza, contact your doctor immediately. 


1. CHOC Children's Blog. 2021. Stomach Flu vs. Influenza - CHOC Children's Blog. [online] Available at: <> [Accessed 4 March 2021].

2. Centers for Disease Control and Prevention. 2021. Similarities and Differences between Flu and COVID-19. [online] Available at: <> [Accessed 4 March 2021].

3. Campbell County Health. 2021. Influenza vs Stomach Flu: What you need to know. [online] Available at: <> [Accessed 4 March 2021].

Disclaimer: This article is written by Practo for informational and educational purposes only. The content presented on this page should not be considered as a substitute for medical expertise. Please "DO NOT SELF-MEDICATE" and seek professional help regarding any health conditions or concerns. Practo will not be responsible for any act or omission arising from the interpretation of the content present on this page.