Boonchai Wedmakawand / Moment

New COVID variants may be linked to a surge in gastrointestinal symptoms across the country.

Research published in the Journal of Clinical Microbiology shows that stomach bugs nearly vanished in one California community during stay-at-home lockdown orders in 2020. But the pathogens have since come roaring back.

People who are sickened by the new COVID variants often complain of abdominal pain, GI bleeding, diarrhea, nausea or vomiting.

Manusapon Kasosod / Moment

A Delta Airlines flight was forced to return to Atlanta after a passenger experienced explosive diarrhea on board.
READ ALSO: Delta Airlines passengers fear they may have been exposed to infectious diarrhea
Cell phone video appeared to show bloody diarrhea on the floor of the cabin. Bloody diarrhea is a sign of infectious diarrhea that can be easily spread via the fecal-oral route.

Corbis via Getty Images

Bruce Springsteen (right) was forced to postpone tour dates to undergo treatment for “symptoms of peptic ulcer disease”. Springsteen, 73, tested positive for COVID in April.

This year’s US Open Grand Slam tennis tournament in New York City has been plagued by a “mysterious” illness marked by GI signs and symptoms.

Al Bello/Getty Images

Austrian player Dominic Thiem (pictured) had to pull out of his second-round match after suffering severe stomach pain, nausea and vomiting. Thiem reportedly threw up and has been ill.

Other tennis players also withdrew from the tournament with GI signs and symptoms. The U.S. Open is being called a superspreader event.