A guaiac test is a test in which the presence of blood is tested in excrement. This test is used to detect bleeding of the large intestine. The wood resin from a tree in the genus of Guajacum is used for this test. When this resin comes into contact with blood it turns blue, thereby indicating the presence of blood.

Machine Briefs:
Option #1: guaiac= GAOE/A*K
Option #2: guaiac= GAO*EK