[Intestinal cryptosporidiosis in suspected acquired immune deficiency].

In a 13-year-old boy--with haemophilia A, positive tests for HTLV-III antibodies, and lymphocytopenia--there occurred watery voluminous stools which persisted over many months. Cryptosporidia were demonstrated microscopically in the stool. Cryptosporidiosis should be considered in patients with acquired immune deficiency who have diarrhoea.