Covid or gastroenteritis: symptoms, how to know?

Diarrhea, nausea, vomiting, stomach ache… These typical signs of gastroenteritis have been reported by Covid-19 positive patients, especially at the start of the epidemic in 2020. Less in 2022 with the release of the variant Omicron. In the risk analysis published by Public Health France in May 2022, diarrhea ranks 11th among symptoms reported by Omicron-positive Covid cases. The nausea and vomiting in 12th grade. How to tell the difference if not by testing yourself? What common points ? What differences between the two ?

What are the common points in Covid and gastro?

Some symptoms are non-specific: headaches, body aches and fatigue which are sometimes seen in gastroenteritis but which can also be present with Covid-19. The chronology in the onset of symptoms, however, makes it quite easy to the distinction between Covid-19 and gastroenteritis. Gastro begins with vomiting and sudden diarrhea, while Covid-19 begins with ENT and respiratory symptoms (cough, runny nose, sore throat). Digestive disorders (diarrhea, stomach aches) appear later. “On the symptomatic level, the distinction between Covid-19 and gastroenteritis is often easy, especially in the common and characteristic forms, but certain atypical cases not so rare can pose a problem.“, explains Dr. Philippe Godeberge, gastroenterologist in Paris. “It therefore happens that it is more difficult during certain atypical forms which create confusion, nuance the specialist. Especially since‘there are forms of Covid-19 that have digestive disorders from the start, sometimes at the forefront. When distinction is not possible, there is only a PCR test which allows you to know if people are positive or not for Covid-19. You can also have both: a Covid-19 infection and gastroenteritis“.

Covid symptoms

In its typical form, Covid-19 manifests as fever, dry cough and ENT symptoms now well known such as a cold, a sore throat or even more characteristic ageusia and anosmia (disappearance of taste and smell). Digestive disorders (diarrhoea, abdominal pain) may appear but “later and in a much more insidious way”, comments the gastroenterologist. And much less in cases positive for the Omicron variant.

Symptoms of a gastro

On the contrary, during an epidemic gastroenteritis, the clinical picture starts in a much more brutal with a profuse diarrhea or even vomiting which exist more rarely in the Covid. Gastroenteritis, in its typical form, is characterized by diarrhea, sudden, watery but relatively brief since it lasts less than 48 to 72 hours, without fever.

What are the differences between gastro and Covid?

► Two different viruses. the virus responsible for Covid-19 is a coronavirus called Sars-CoV-2. “If gastroenteritis can be caused by a virus, a bacterium or a parasite, epidemic gastroenteritis in winter is almost exclusively of viral origin. says the specialist. In adults, the most common gastrointestinal virus is norovirus while in children it is more the rotavirus. Bacterial gastroenteritis often follows the ingestion of contaminated food or water: salmonellosis, Escherichia coli or Campylobacter. As for parasitic gastroenteritis, which is rarer, it often occurs after returning from a trip to a tropical country (amoebas for example). “The incriminated germ can be detected by bacteriological and parasitological examination of stools (unlike viruses which are not detected by routine examinations)”he continues.

Fever is rare in viral gastroenteritis.

►The context : it allows you to direct towards Covid-19 if you are a contact case or an exposed profession. “The risk increases in the event of identified risk factors such as hypertension, overweight, diabetes, cardiovascular history or disease weakening the immune system. Whereas for gastroenteritis, the context is different. We were in contact rather with children or with someone who has already had gastroenteritis”, notes Dr. Philippe Godeberge.

► Fever : this is rare in standard viral gastroenteritis (slightly more present in children) whereas it is frequently reported by Covid cases. “However, gastroenteritis, linked to bacteria, is more likely to be very febrile, recognizes the gastroenterologist. But here again, the context must be taken into account (return from a country at risk, antibiotic treatment, collective catering), etc…

► The duration of the disease: gastroenteritis usually lasts between 24 and 72 hours while the symptoms of Covid-19 settle longer (incubation period of about 3 days for a average duration of 5 days with Omicron).

Are the intestinal symptoms the same?

Abdominal pain and diarrhea: they are more common in Covid-19 than in gastroenteritis, which is often accompanied by profuse diarrhea but moderate abdominal cramps.

What to do in case of doubt?

“It is important to emphasize that the precautions taken in the context of the fight against the coronavirus will probably make it possible to reduce the peak frequency of gastroenteritis, rejoices Dr. Philippe Goderberge. This is what we observed during the H1N1 epidemic in 2009 during which the amount of gastroenteritis was much more modest because we took a lot of precautions. It is therefore very important to respect barrier gestures such as washing your hands regularly, coughing and sneezing into your elbow… Finally, if in doubt, do not hesitate to go for a coronavirus screening test: a pharmacy antigen test or one lab PCR test (More reliable). The self-tests are not recommended in the event of symptoms suggestive of Covid.

What are the signs of complications to watch out for?

Viral gastroenteritis is a common pathology that usually disappears in 48 to 72 hours. When bacterial, it can last up to two weeks. In its mild form, the main risk of gastroenteritis is dehydration due to diarrhea and vomiting, it is therefore essential to prevent it, especially in infants and the elderly. The presence of mucus or blood in the stool should also alert. With regard to Covid-19, it is the breathing difficulties that must lead to immediately call 15.

Thanks to Dr Philippe Godeberge, gastroenterologist in Paris.