Stomach Bug, COVID-19, or Flu: How to Tell

A Woman holding her stomach.

Stomach Bug, COVID-19, Flu, or Serious GI Issue?  How to Tell
COVID-19 cases around the country are increasing as we head into the winter months, a time when illnesses are on the rise – including stomach bugs (gastroenteritis) and seasonal flu. Symptoms of common winter bugs may include fever, cough, and gastrointestinal issues like nausea, vomiting, and diarrhea. These can also be symptoms of COVID-19, which can lead people to wonder whether they have COVID-19 or another common infection.
As with any medical issue you experience, it is always best to contact your doctor or visit an Urgent Care Center if you need medical care or have questions about your health.  If you have any symptoms of a stomach bug, COVID-19, or flu, you should self-isolate until your symptoms resolve or you have a firm diagnosis from a medical professional.

How to Tell if You Might Have Gastroenteritis/Stomach Bug

Millions of people get gastroenteritis every winter. Here are some facts:  
  • Though it is sometimes referred to as “stomach flu,” viral gastroenteritis is not related to the influenza virus that causes the flu, it is caused by other viruses like Norovirus or Rotavirus.
  • Viral gastroenteritis is highly contagious and symptoms usually develop within 1-2 days after exposure to someone with the illness.
  • Typical symptoms include abdominal pain, nausea, vomiting, and diarrhea. Fever occurs in about half of patients. People are usually sick for approximately 2-3 days.
  • Milder infections in healthy people can often be managed at home, but people with more severe symptoms should seek medical attention.

How to Tell if Your GI issues Might Be COVID-19

If you experience new GI symptoms, follow these guidelines:
  • Research consistently shows that approximately 5-10% of adults with COVID-19 report GI symptoms such as nausea, vomiting, or diarrhea. Typically, patients who have GI symptoms of COVID-19 will also have the more common upper respiratory symptoms that accompany COVID-19, such as a dry cough or difficulty breathing. However, sometimes the GI symptoms will come first and the respiratory symptoms will follow a day or so later.
  • If you have new GI symptoms like nausea, vomiting, or diarrhea - watch for fever, cough, or shortness of breath over the next few days. If you develop these respiratory symptoms, call your doctor and ask if you should be tested for COVID-19
  • Do not worry alone – call your doctor with any questions you have about your symptoms.

Symptoms Common in COVID-19 and Flu

Here are some symptoms that are common in both COVID-19 and seasonal flu:
  • Fever
  • Body aches
  • Cough
If you have these symptoms, you should call your doctor to ask about COVID-19 and Flu testing. Remember to isolate yourself if you have any symptoms. Avoid public places and contact with others while waiting for testing and results.

How to Tell if You Might Have a Serious GI Issue

Some symptoms  are not expected with a stomach bug or COVID-19 and may indicate a more serious gastrointestinal condition like colon cancer, stomach ulcers, or Crohn’s Disease. Call your doctor or seek medical help if you experience any of these symptoms:
  • Blood in your vomit or your stool
  • GI symptoms that lead to weight loss
  • GI symptoms lasting longer than one week

Stomach Bug, COVID-19, Flu, or Serious GI Condition

Refer to this chart to compare symptoms associated with gastroenteritis, COVID-19, flu, and serious GI conditions. It is always best to contact your doctor to discuss any symptoms you are experiencing. Your primary care physician, gastroenterologist, or a local Urgent Care center can assess your condition and give you an order for a COVID-19 test if needed.
Stomach Bug
COVID-19 Flu Serious GI Condition
Nausea Yes Sometimes Sometimes Sometimes
Vomiting Yes Sometimes Sometimes Sometimes
Abdominal Pain Yes Sometimes Sometimes Sometimes
Diarrhea Yes Sometimes Sometimes Sometimes
Blood in Stool No No No Often
Fever Sometimes Yes Yes Sometimes
Fatigue Yes Yes Yes Yes
Body Aches Yes Yes Yes Sometimes
Weight Loss No No No Yes
Loss of Taste/Smell No Yes Rarely No

GI Podcast: About Stomachaces 

Dr. John Dowd of Emerson Gastroenterology Associates discusses the causes of stomachaches and when you should visit a GI specialist.

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Thank you for reading our article on COVID-19 symptoms. As a community hospital we rely on the support of our community to continue to provide our local health care needs. We welcome your help in fostering a healthy community. If this content has helped you in an way, please consider making an online gift to Emerson Hospital so that we can continue to support our community’s health needs.


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