ABSTRACT
A 42-year-old American male researcher contracted schistosomiasis from environmental sources in the course of his observations on human behavior in Upper Egypt. After a long asymptomatic period, he developed various symptoms and Schistosoma haematobium was found in a urine examination. After treatment with Metrifonate, urine examination became negative. However, abdominal pain persisted and most diagnostic tests were negative. Colonoscopic examination and biopsy of the mucosa revealed schistosomiasis. Treatment with Praziquantel was thoroughly effective in clearing the persistent Schistosoma haematobium infection. It is necessary to maintain a high index of suspicion in cases of potential schistosomiasis. The availability of nontoxic treatment is discussed.