The Cowlitz County Health Department is investigating one confirmed and one probable case of E. coli in children who visited the Willow Grove Gardens Pumpkin Patch and petting zoo in Longview.The children became ill after visiting the farm earlier this month. One child was hospitalized for several days but is now recovering.E. coli is a bacterial infection that can cause nausea, vomiting and diarrhea that could be bloody. Children with symptoms should see a health care provider immediately. E. coli can cause kidney damage and is potentially fatal.Farm animals can carry E. coli and shed the bacteria in their stool. Animal hide can easily become contaminated; children and adults can get the infection simply by petting the animals. Touching the eyes, nose or mouth after contact with a contaminated surface is a major route of infection.Anyone visiting a petting zoo or having contact with farm animals should wash their hands with soap and water immediately after contact with animals.Health officials are asking anyone who visited the Willow Grove Gardens Pumpkin Patch and is experiencing symptoms of E. coli illness to call the Cowlitz County Health Department at 360-414-5599.