RESUMEN
Mucosal biopsies from the rectum and colon of 25 males of pure urinary bilharziasis and negative stools were examined directly in the fresh state for bilharzial oval pattern by a slide compression technique. The method proved valuable in the diagnosis of bilharzial nature of the disease as a supplement to routine urine and stool examination. It has the additional balue of indentifying the species of bilharzia in the different levels of rectum and colon. This showed that the bilharzial oval pattern in patients with pure urinary bilharziasis is dominatly that of pure haematobium and dominant haematobium at 10 cm level as compared to a dominant pattern of pure mansoni and dominant mansoni at cm level irrespective of the presence of recent or past history of anti-bilharzial therapy and finally we can conclude that occuld mansoniasis is common in our locality and is discovered only by mucosal biopsy particularly colonic biopsy