fecal immunochemical test
Colorectal cancer screening test that detects human hemoglobin in stool samples using antibody-based technology.
Full Definition
The fecal immunochemical test is a noninvasive colorectal cancer screening method that uses antibodies specific to human hemoglobin to detect blood in stool samples. FIT offers advantages over guaiac-based tests including no dietary restrictions, single-sample collection, and improved specificity for lower gastrointestinal bleeding. The test is typically performed annually and serves as either a primary screening modality or as part of organized screening programs. Positive FIT results require follow-up with diagnostic colonoscopy to identify the source of bleeding and evaluate for colorectal neoplasia.
Usage
Usage note: Distinguish from guaiac-based FOBT; emphasize annual testing requirement.
In Context
- "Annual fecal immunochemical testing is recommended for average-risk patients declining colonoscopy." — Screening guideline
- "The laboratory reported a positive FIT result requiring urgent colonoscopy referral." — Laboratory report