Delta Air Lines' transatlantic flight was forced to turn back after a passenger had a severe case of diarrhea, according to multiple reports.

Flight DL194, traveling from Atlanta to Barcelona, ??was supposed to make a U-turn near Virginia on Friday, data from Flightradar24 shows. An audio transmission between pilots and air traffic control recorded by LiveATC.com was shared by an aviation enthusiast on Twitter.

"It's just a matter of biohazard," the pilot is heard saying. "We had a passenger who had diarrhea the whole way on the plane, so they want us to go back to Atlanta."

Maintenance crews spent five hours cleaning the plane after the forced landing, including replacing the carpet, which had become dirty along its entire length.

People on social media wrote that the team began cleaning, disinfecting and scenting the area, although spraying the vanilla scent only made the heavy air worse.

Such stools can contain a variety of different microbes including any pathogens that may have caused the diarrhea in the first place.

The passengers, including one suffering from diarrhoea, were allowed to board again after eight hours and went to Barcelona on Saturday afternoon without further incident.