Lol! It's not actual poop. Fecal contamination means the meat or veggies have come into contact with bacteria from poop.
That's easy to do in today's mass meat producing farming factories. Cows cooped up around other sick cows and shytting everywhere.
But cooking meat properly eliminates the bacteria. Also grass fed, open range meat is less likely to have this issue for obvious reasons.
The more concerning part is how the cocktail of antibiotics given to these animals is causing superbugs resistant to any antibiotics.