A children's book about the importance of handwashing, drinking clean water, and avoiding contaminated food for good health. Stan, a 3rd grader, goes to school and encounters a virus, a bacterium, a protozoan, and a parasitic worm, all of which can cause abdominal pain and diarrhea. By taking simple precautions, he can avoid getting sick from these diseases. This book is appropriate for children in grades 3 through 6.