High-sensitivity fecal occult blood tests (FOBT): FOBT checks for tiny amounts of blood in the stool that cannot be seen visually. The Food and Drug Administration (FDA) has approved two types of FOBT to screen for colorectal cancer: guaiac FOBT (gFOBT) and the fecal immunochemical test (FIT, also known as iFOBT). In these tests, stool samples are collected by the patient using a kit, and the samples are returned to the doctor.
Stool DNA test (FIT-DNA): The DNA test is approved by the FDA. Similar to FIT, it is a multi-target test that detects tiny amounts of blood in the stool. It also detects nine DNA biomarkers in three genes found in colorectal cancer and pre-cancerous advanced adenomas.