The symptoms of a shiga toxin-producing E. coli infection include severe abdominal cramps, diarrhea that may be watery and/or bloody, a mild fever, nausea, and vomiting. Symptoms usually begin about three to four days after exposure to the pathogenic bacteria, sometimes up to ten days later. Children under the age of 5 are most susceptible to serious complications from this infection, most notably hemolytic uremic syndrome (HUS).