Incidence of amebiasis in patients with positive guaiac test of the stool

Summary 1. Of 50 individuals who had a positive guaiac test of the stool after having been on a meat-free diet for 3 days or longer, only 1 (2 per cent) hadE. histolytica in the stool on a single examination.2. Since 2 per cent represents the predicted incidence of amebiasis in the general population of Strang Clinic patients (on examination of a single casual specimen), it was concluded that, in general, positive guaiac tests are not due to amebiasis.3. This does not preclude the possibility that in certain instancesE. histolytica may produce sufficient intestinal disease to be responsible for positive guaiac tests.Dr. Emerson Day, Director of the Strang Clinic, cooperated in these studies, and Dr. Louis Venet also offered valuable assistance.Mrs. Patricia Daniels, The Central Laboratories, The New York Hospital, examined the stool specimens. Miss Mary Sukany performed the guaiac tests on the stools.