Catching COVID-19 can cause long-term gastrointestinal problems such as constipation and diarrhoea, a study has found.
Other such symptoms that stayed with people up to a year after infection were chronic acid reflux, bloating, and stomach pain.
The US study was based on the medical records of more than 11.6 million people, 154,000 of whom had the coronavirus between March 2020 and January 2021.
They were compared with 5.6 million people who did not catch the disease in that period, and research from some 5.8 million people taken before the outbreak.
Researchers found that those who had the virus experienced more gastrointestinal symptoms a year later than those who did not catch it, and the average pre-pandemic person.
‘Destructive even for healthy people’
Epidemiologist Ziyad Al-Aly, a senior author on the study at Washington University, said it was “increasingly clear” that the gastrointestinal tract (the key route through your digestive system) was a “reservoir” for COVID-19.
“The virus can be destructive, even among those considered healthy or who have had mild infections,” he said.
Symptoms tended to be more likely among those who were more immediately impacted by the disease, such as anyone who was admitted to hospital.
But they were relatively common overall, with gastrointestinal issues 36% more likely in people who were infected.
The study found COVID-19 made people 54% more likely to develop signs of irritable bowel syndrome, and digestive symptoms such as constipation, bloating, diarrhoea.
People were 35% more likely to have acid reflux disease.
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It comes after a SAGE study found that most long COVID patients still have organ damage after a year.
People have reported a huge range of symptoms in the years since the outbreak, including depression, headaches, respiratory problems, hair loss, and persistent changes to smell and taste.
According to other research published earlier in 2023, those who suffered milder disease during infection should see any long-term effects resolve in a year.
The latest study, however, says its findings reflect the “urgent need to double down and accelerate our effort to develop strategies to prevent and treat the long-term health effects” of coronavirus.
The results were published in the journal Nature Communications.