![Chris “The Chiu Man" Chiu, MD on Twitter: "5/ gFOBT works by detecting pseudoperoxidase in hemoglobin. A positive result occurs if the testing paper containing a stool specimen turns blue after adding Chris “The Chiu Man" Chiu, MD on Twitter: "5/ gFOBT works by detecting pseudoperoxidase in hemoglobin. A positive result occurs if the testing paper containing a stool specimen turns blue after adding](https://pbs.twimg.com/media/EFl5WS4XUAEtqvj.jpg:large)
Chris “The Chiu Man" Chiu, MD on Twitter: "5/ gFOBT works by detecting pseudoperoxidase in hemoglobin. A positive result occurs if the testing paper containing a stool specimen turns blue after adding
![Guaiac test card interpretation. Two spots of stool sample are smeared... | Download Scientific Diagram Guaiac test card interpretation. Two spots of stool sample are smeared... | Download Scientific Diagram](https://www.researchgate.net/publication/232744448/figure/fig1/AS:300355842789380@1448621821320/Guaiac-test-card-interpretation-Two-spots-of-stool-sample-are-smeared-on-the-opposite.png)
Guaiac test card interpretation. Two spots of stool sample are smeared... | Download Scientific Diagram
![Table 3 from The Role of Fecal Occult Blood Testing in Screening for Colorectal Cancer COLORECTAL CANCER: AN UPDATE FOR DIAGNOSIS AND PREVENTION, SERIES #3 | Semantic Scholar Table 3 from The Role of Fecal Occult Blood Testing in Screening for Colorectal Cancer COLORECTAL CANCER: AN UPDATE FOR DIAGNOSIS AND PREVENTION, SERIES #3 | Semantic Scholar](https://d3i71xaburhd42.cloudfront.net/4940f33b3e2e8bd798c16e47828e2cdbd1bd3421/2-Figure2-1.png)