Signs and symptoms of E. coli O157:H7 infection usually begin three or four days after exposure to the bacteria. But you may become ill as soon as one day after exposure to more than a week later. Signs and symptoms include: E. coli  Diarrhea, which may range from mild and watery to severe and bloody Stomach cramping, pain or tenderness Nausea and vomiting, in some people 
signs symptoms e  coli o157:h7 infection begin days exposure bacteria  may ill soon day exposure week later  signs symptoms include: e  coli  diarrhea  may range mild watery severe bloody stomach cramping  pain tenderness nausea vomiting  people 
e coli