Giardiasis with total villous atrophy.

A patient who developed symptomatic giardiasis after a tour of the Soviet Union is presented. The diagnosis was established by duodenal aspiration. A small intestinal biopsy revealed total villous atrophy in the absence of celiac sprue or a gastrointestinal immunodeficiency syndrome, a finding not previously described. The biopsy remains normal after a single course of metronidazole (Flagyl), despite subsequent exposure to gluten.