1. Infected people excrete whipworm eggs in stool.
2–3. In the soil, the eggs mature. After 15 to 30 days, they can cause infection.
4. The eggs may be swallowed when hands or food are contaminated with stool that contains whipworm eggs or soil that contains such stool.
5. The eggs hatch in the small intestine and release larvae.
6. The larvae mature and establish themselves as adults in part of the large intestine (called the cecum). The female whipworms produce eggs.
Image from the Centers for Disease Control and Prevention, Global Health, Division of Parasitic Diseases and Malaria.