• Are gastrointestinal symptoms a sign of COVID-19?
• Is Omicron causing more gastrointestinal symptoms?
• How to avoid an upset stomach
• Help us track the nation’s health
  

If you’ve had a dodgy tummy lately, you’re not alone. We’ve noticed a recent rise in people reporting gastrointestinal symptoms in the ZOE COVID Study app through January 2022.

So is this due to the Omicron COVID variant? Or is there something else going on? Here’s what we know so far. 

Is an upset stomach a sign of COVID-19?

Thanks to millions of daily health reports from our dedicated ZOE COVID Study app contributors, we’ve shown that gastrointestinal problems such as diarrhoea, stomach pains, feeling sick and losing your appetite or skipping meals can all be symptoms of COVID-19 right from the earliest days of the pandemic.

Back in April 2020 we were also able to show that these kinds of symptoms tended to cluster together, forming one of six distinct ‘types’ of COVID-19.

We’ve recently spotted a sharp increase in the number of people reporting gastrointestinal symptoms in the app from mid-December 2021 through January 2022. 

Interestingly, this follows roughly the same pattern that we saw during the winter wave a year ago. The blue line in the chart below shows the proportion of people reporting gastrointestinal symptoms in the app this year, while the orange line is from the same time last year.

Is Omicron causing more gastrointestinal symptoms?

Throughout the past two years, we’ve seen changes in the patterns of symptoms reported in the app as new variants have emerged and more of the population had one, two, three or even four doses of vaccine.

Gastrointestinal symptoms were a common hallmark of COVID-19 earlier on in the pandemic with the original version of the virus, as well as the Alpha and Delta variants. So we were curious to know whether the increase we’re seeing now was linked to the recent rise of the Omicron variant. 

However, when we looked at PCR test results reported in the app, we found that while a significant proportion of people reporting gastrointestinal symptoms tested positive, we also saw an increase in the proportion of people with these symptoms who tested negative. There was a similar pattern with lateral flow test results.

This suggests that even though Omicron can be associated with gastrointestinal symptoms, the rates are not higher than what we saw in Delta, and one or more other types of tummy bug are likely to be going around in the population at the current time.

For example, norovirus is very common at this time of year - hence its nickname, the Winter Vomiting Bug - although we currently have no way of testing whether people reporting gastrointestinal symptoms in the app are infected with it. 

How to avoid an upset stomach

After two years of singing Happy Birthday in the bathroom and slathering on hand sanitiser, we now know that washing your hands isn’t always so relevant for avoiding COVID-19. 

However, remembering to wash your hands after using the bathroom or being in other public or dirty environments will help to reduce your risk of catching a tummy bug.

Similarly, good food hygiene practices like washing your hands before cooking and eating or after handling raw meat and making sure that food is cooked properly will help to protect against food poisoning. 

We also know that there’s a strong connection between our health and the microbes living in your gut (known as the gut microbiome). Changing your diet can influence the range of microbes in the gut, and research shows that eating a diverse, plant-rich diet is associated with a healthier, more diverse microbiome too.

Help us track the nation’s health

These latest results show that the ZOE app is not only a powerful tool for studying COVID-19, but also for looking more broadly at the nation’s health. This is something we’ll be doing in more detail with our wider health studies, which we’re rolling out through the app over the coming months.

The pandemic still isn’t over, so we need as many people to keep logging daily health reports in the app to provide a picture of how COVID-19 is spreading in the UK and how the symptoms are changing in response to new variants and vaccines. 

We’re also thrilled that more than 800,000 contributors have agreed to take part in further research to tackle some of the biggest health problems we face today, including heart disease, cancer and dementia.

Whether you just want to help us track COVID-19, or if you want to contribute to wider health science, download the ZOE app today and get involved in the future of health research. 

Stay safe and keep logging.