1. How is defecate occult blood caused?

2. The conventional stool plus occult-blood of the patients before and after the treatment are all normal except 1 case of hemorrhoids hematochezia.

3. Benzidine: [ ben´zĭ-dēn ] a compound formed by the action of acids on hydrazobenzene, once widely used in testing for occult blood; its use is now limited because it is toxic and carcinogenic.

4. The principle of chemical tests to detect occult blood is based on the fact that hemoglobin and its derivatives react in a similar way to peroxidase enzymes– by catalyzing the transfer of an oxygen atom from the peroxide to a chromogen such as Benzidine, o-toludine, guaiac or aminophenazone.Oxidation of the chromogen is indicated by the production of a blue, blue-green or …