A case is described of a nonimmunocompromised man who presented with diarrhea, weight loss, and microcytic anemia. Colonoscopy revealed a pancolitis characterized by aphthoid ulceration on endoscopy and intense tissue eosinophilic infiltrates on biopsy. Both colonic biopsies and stool aspirates revealed the larvae of Strongyloides stercoralis, thus confirming this parasite as the causative agent for the colitis.