A Fecal Immunochemical Test (FIT) screens for hidden human blood in your stool, primarily from the lower gastrointestinal tract. This test is a valuable tool for early detection of potential issues, including colorectal cancer, before symptoms appear.
Understanding a Positive Result
A positive FIT result means human blood was detected in your stool. This does not automatically indicate cancer. The FIT is a screening test, not a diagnostic one; it signals a need for further investigation, not a definitive diagnosis. It detects minute, often invisible, amounts of blood, indicating potential bleeding in the digestive tract. While warranting attention, a positive result should not cause immediate alarm.
Next Steps After a Positive Result
Following a positive FIT, a diagnostic colonoscopy is the standard next step. This procedure allows a gastroenterologist to examine the colon and rectum using a colonoscope, a flexible tube with a camera. During the colonoscopy, the doctor can visualize the bowel, identify bleeding sources, and remove polyps or take tissue samples for analysis.
Preparation involves dietary adjustments and a laxative solution to cleanse the bowels for a clear view. Sedation is typically administered for comfort during the 30-minute procedure. The overall process, including preparation and recovery, takes several hours. After monitoring, you will need a ride home and can usually resume light activities within 24 to 48 hours.
Potential Causes of a Positive Result
A positive FIT result can stem from various conditions, not solely cancer. Common non-cancerous causes include hemorrhoids (swollen veins) and anal fissures (small tears) in the rectum or anus. Diverticulosis, where small pouches form in the colon wall, can also lead to bleeding. Inflammatory bowel diseases (IBD) like Crohn’s disease or ulcerative colitis, and ulcers in the stomach or intestines, are other potential sources of blood.
Polyps, which are growths on the lining of the intestines, are also a frequent cause of positive FIT results. While many polyps are benign, some can be pre-cancerous and have the potential to develop into cancer over time. These growths can bleed when stool passes, leading to a positive test. Certain medications, like blood thinners or aspirin, can also contribute to bleeding in the digestive tract.
The Importance of Follow-Up
Completing the recommended follow-up, especially a colonoscopy, after a positive FIT result is important. Timely follow-up allows for detecting and removing pre-cancerous polyps, preventing colorectal cancer. If cancer is present, early detection significantly improves treatment outcomes. Delaying a colonoscopy can increase the risk of advanced-stage disease, so acting on a positive result helps address potential issues early.