Trichuris humans acquire the infection by eating foods contaminated with infective eggs. Once eggs are swallowed, the larvae hatch in the small intestine, where they mature and migrate to the colon. Trichuris infections with a low worm burden are usually asymptomatic, but infections of moderate to heavy worm loads present with lower abdominal pain, distention, and diarrhea. Severe infection may lead to profuse bloody diarrhea, cramps, tenesmus, urgency, and rectal prolapse. Occasionally worms migrate to the appendix, causing appendicitis. Jawetz microbiology 27e 724.