Diarrhea as a symptom of the Coronavirus (COVID-19)


Updated Dec 2021

Diarrhea. You know if you have THIS digestive condition. People who suffer from diarrhea experience loose, watery stools more frequently than normal and often experience a sense of urgency to go. Generally, there are two types of diarrhea, acute and chronic. Acute diarrhea lasts a short time, about three to 5 days. Chronic diarrhea is usually related to other digestive disorders such as irritable bowel syndrome or inflammatory bowel disease and may last for as long as you have the illness. Diarrhea has been added as a symptom of the coronavirus (COVID-19).

According to the World Health Organization, the most common symptoms of COVID-19 are:

Symptoms of COVID-19 can vary from person to person. They may also vary in different age groups.

Symptoms may take up to 14 days to appear after exposure to COVID-19.

COVID-19 vaccines are all highly effective at preventing severe COVID-19 illness and death. However, vaccines are rarely 100% effective and you may still become infected with or without symptoms.

Some of the more commonly reported symptoms include:

  • new or worsening cough
  • shortness of breath or difficulty breathing
  • temperature equal to or more than 38°C
  • feeling feverish
  • chills
  • fatigue or weakness
  • muscle or body aches
  • new loss of smell or taste
  • headache
  • abdominal pain, diarrhea and vomiting
  • feeling very unwell

This list does not include all possible symptoms. Some people become infected but don’t develop any symptoms or feel unwell at all!

The Government of Canada indicates that common reported symptoms may be broadly categorized as “more frequent”, “less frequent” and “rare” (Table below). Diagnosis should always be confirmed by laboratory testing, and you should seek medical consultation if experiencing new or worsening symptoms.

More frequent (>50%)Less frequent (<50%)Rare (<10%)
New or worsening cough
Fatigue and myalgia
Gastrointestinal symptoms (nausea, vomiting, diarrhea)
Shortness of breath or difficulty breathing
Sore throat
Painful and/or difficulty swallowing
New or unusual exacerbation of chronic conditions
Decreased or loss of appetite
New loss of smell and/or taste
Skin manifestations
Runny/stuffy nose
Eye manifestations
Note: Symptoms among older adults (65 years of age and older) and those with underlying medical conditions may be atypical or subtle; for instance they may be more likely to present without fever or respiratory symptoms. Source here.

We’ve seen the most common list of COVID-19 symptoms repeatedly on the TV, in news articles, and from our friends and family. However, as doctors learn more about COVID-19, a study has shown that digestive symptoms, in particular diarrhea, could be a symptom for people who have a mild form of COVID-19 (without difficulty breathing or low blood oxygen levels).  In this study published in the American Journal of Gastroenterology, patients in this unique sub-group showed that diarrhea can be the initial presentation of COVID-19, and patients may only later or never present respiratory symptoms or a fever.

In more detail, this study showed that 23% of patients were admitted with digestive symptoms, 43% with respiratory symptoms only, and 33% with both respiratory and gastrointestinal (gastro) symptoms. Among the patients with gastro symptoms, 67% of them had diarrhea, and 20% experienced diarrhea as the first symptom of their illness. Diarrhea lasted an average of 5 days, and about one-third of patients with gastro symptoms never experienced a fever. The study also found that those with gastrointestinal symptoms were much more likely to have the coronavirus (SARS-CoV-2) detected in their stool samples, with about 73% of patients testing positively compared with 14% of those with respiratory symptoms only. 

The authors of this study note that because gastro problems are so common, having diarrhea doesn’t necessarily mean that a person has COVID-19.  But this study does tell us that diarrhea can be a vital warning-sign. If patients experience new-onset gastrointestinal symptoms after possibly coming into contact with someone who has COVID-19, they should be suspected for the illness, EVEN in the absence of cough, shortness of breath, sore throat, or fever.

This study came about after previous research, also published in the American Journal of Gastroenterology found that 50% of a group of 200 patients with COVID-19 in Wuhan, China reported at least one gastro symptom, with 18% reporting diarrhea, vomiting, or abdominal pain. This study focused on patients with severe COVID-19, rather than a mild form.

It’s important to note that both studies were relatively small, so larger studies are needed to describe digestive symptoms in patients with COVID-19.

More recently, according to a review by University of Alberta, nearly one in five people with COVID-19 may only have gastrointestinal symptoms, according to researchers. Gastrointestinal symptoms associated with COVID-19 vary widely but can include loss of appetite, nausea, vomiting, diarrhea and generalized abdominal pain. The researchers who conducted the review report that 18 per cent of patients presented with such symptoms, while 16 per cent of COVID-19 cases may only present with gastrointestinal symptoms.

“There’s a growing amount of literature showing that abdominal symptomatology is a common presentation for COVID-19,” said Mitch Wilson, a radiologist and clinical lecturer in the University of Alberta’s Faculty of Medicine & Dentistry.

Read more here.

Not sure if your stool is healthy or not? Learning more about how colour, texture and frequency of poop can help you identify when you should speak to your doctor about your stools.

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