Digestive issues like diarrhea could be the first sign of coronavirus infection, according to a new study.

Although most patients with COVID-19 have respiratory symptoms, the Wuhan Medical Treatment Expert Group for COVID-19 found that many patients also had digestive problems in the early stages of the outbreak in Wuhan, China.

Specifically, 99 of the 204 researched patients with COVID-19, 48.5 percent, had digestive symptoms as their “chief complaint,” according to the study published in the American Journal of Gastroenterology on Wednesday.

These digestive issues include diarrhea, vomiting and abdominal pain.

“Clinicians should recognize that digestive symptoms, such as diarrhea, may be a presenting feature of COVID-19, and that the index of suspicion may need to be raised earlier in at-risk patients presenting with digestive symptoms rather than waiting for respiratory symptoms to emerge,” the researchers said.

Of the 99 cases with digestive symptoms, seven patients reported not having any respiratory problems, which has been one of the most common signs of the coronavirus.

The study also found that there was a larger gap in time between illness onset and hospital admission for patients with digestive symptoms than patients without (nine days vs. 7.3 days).

This suggests that patients with digestive issues waited longer before going to the hospital because they didn’t suspect they had the coronavirus.

The study also found that patients without digestive symptoms were more likely to be cured than those who reported digestive symptoms (60 percent compared to 30.4 percent).

“In this study, COVID-19 patients with digestive symptoms have a worse clinical outcome and higher risk of mortality compared to those without digestive symptoms, emphasizing the importance of including symptoms like diarrhea to suspect COVID-19 early in the disease course before respiratory symptoms develop,” American Journal of Gastroenterology Co-Editor-in-Chief Brennan M.R. Spiegel said in a news release.

“This may lead to earlier diagnosis of COVID-19, which can lead to earlier treatment and more expeditious quarantine to minimize transmission from people who otherwise remain undiagnosed.”

The study found that as the severity of the virus increased, the digestive symptoms became even more serious.

“This is important because if clinicians solely monitor for respiratory symptoms to establish case definitions for COVID-19, they may miss cases initially presenting with extra-pulmonary symptoms, or the disease may not be diagnosed later until respiratory symptoms emerge,” the study authors wrote.

The researchers acknowledged that more studies needed to be conducted in order to evaluate the “prevalence, incidence, predictors, and outcomes of digestive symptoms in this still emerging pandemic.”

As of Friday morning, there were more than 263,000 confirmed cases of coronavirus across the world.

There have also been at least 10,444 fatalities, though 87,351 people have recovered from the virus.

In the United States, there were 14,631 confirmed cases and 210 fatalities as of Friday.