Endoscopic Fecal Immunochemical Test for Occult Blood Trends (FIT Trends)

What This Test Measures

The test detects the presence of hemoglobin (a protein in blood) in stool samples collected during an endoscopic procedure. While not a standalone diagnostic tool, it provides a quantitative measure of occult blood levels that may indicate bleeding sources, such as ulcers, polyps, or other gastrointestinal issues.

Why It’s Done

Your healthcare provider may order this test if you have a history of gastrointestinal bleeding, symptoms like unexplained fatigue, anemia, or changes in bowel habits, or if you’re undergoing surveillance for conditions like colorectal cancer.

Sample Collection and Procedure

During an endoscopic procedure, small stool samples are collected from different areas of your gastrointestinal tract. These samples are then tested for hidden blood content using a sensitive chemical method, often involving color changes to detect hemoglobin.

Interpreting Results

Results are typically reported as a trend over time rather than a single absolute value. A consistent increase in occult blood levels may signal ongoing bleeding, prompting further investigation such as additional endoscopy or imaging studies.