Schistosoma /shis′təsō″mə/ [Gk, schistos, cleft, soma, body] , a genus of blood flukes that may cause urinary, GI, or liver disease in humans and that requires fecal contamination of water and freshwater snails as intermediate hosts. Schistosoma haematobium, found chiefly in Africa and the Middle East, affects the bladder, ureter, and pelvic organs, causing painful frequent urination and hematuria. S. japonicum, found in Japan, the Philippines, and Eastern Asia, causes GI ulcerations and fibrosis of the liver. S. mansoni, found in Africa, the Middle East, the Caribbean, and tropical America, causes symptoms similar to those caused by S. japonicum. Also called Bilharzia. See also schistosomiasis.