Holy water may not be as pure as its name implies.

A new Austrian study found that 86 percent of holy water, used in baptismal ceremonies and to wet congregants’ lips, had fecal matter such as E. coli, enterococci and Campylobacter -- diseases that lead to fever, diarrhea and abdominal pain, ABC News reports.

"We need to warn people against drinking from these sources," study researcher Alexander Kirschner said.

The study, published in the Journal of Water and Health, also analyzed water from holy springs -- water sources that gained their reputation in medieval times for having healing capabilities. From the 21 springs and 18 fonts tested in Austria, scientists found samples of 62 million bacteria per milliliter of water, none of it safe to drink.

“In those days, the quality of the water in towns and cities was generally so poor that people were constantly developing diarrhea or other diseases. If they then came across a protected spring in a forest that was not as polluted and drank from it for several days, their symptoms disappeared,” Kirschner said in a statement. “So although in those days they were drinking healthier water, given the excellent quality of our drinking water today, the situation is now reversed.”

Nitrates were identified in water samples. If ingested, nitrates could cause serious health problems in children under 6 months old and could lead to death if left untreated, according to the U.S. Environmental Protection Agency.

While there have been few reported incidents of health problems caused by holy water, Kirschner says the problem is out there.

"This may represent a problem that has hitherto been underestimated, especially in hospitals, since there's a lot of people with weakened immune systems there," he said. The study calls for “proper water quality management” in both holy water at popular churches and holy spring sites.

While a previous study showed salt content of 20 percent in holy water halted the spread of bacteria, it may not be the best solution. "The addition of salt cannot be regarded as a reliable means of disinfection,” Kirschner said.

The team suggests replacing holy water on a regular basis and for local officials to check the water quality of holy springs to see if it’s suitable to drink.