Colitis due to Ancylostoma duodenale.

The larva of hookworm matures into the adult stage in the small intestine, causing chronic intestinal blood loss and iron-deficiency anemia. Hookworm infestation of colon has not been reported previously. We report a 35-year-old man who presented with diarrhea with blood and mucus in stools. Colonoscopy revealed several hookworms in the colon firmly adherent to the mucosa, with oozing of blood and surrounding mucosal erosions. He was treated with mebendazole and symptoms recovered completely.