Adult whipworms are found in the large intestine. Infection occurs through ingestion of eggs and is more common in warmer areas. Whipworms eggs are passed in the feces of infected persons, and if an infected person defecates outside or if untreated human feces as used as fertilizer, eggs are deposited on soil where they can mature into an infective stage.
Ingestion of these eggs "can happen when hands or fingers that have contaminated dirt on them are put in the mouth or by consuming vegetables or fruits that have not been carefully cooked, washed or peeled." The eggs hatch in the small intestine, and then move into the wall of the small intestine and develop.
