Symptoms

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:

• Diarrhea, which may range from mild and watery to severe and bloody
• Stomach cramping, pain or tenderness
• Nausea and vomiting, in some people

When to see a doctor

Contact your doctor if your diarrhea is persistent, severe or bloody.