Positive FIT Test: What It Means and What to Do Next
A positive FIT test means the lab found blood in your stool sample. It does not mean you have cancer. It does mean you need a follow-up colonoscopy, so a doctor can look at your colon directly and find where the blood is coming from. Repeating the stool test is not the next step. Booking the colonoscopy is.
Getting a call about an abnormal result is unsettling. This guide explains what the result tells you, what else can cause it, how quickly to act, what happens at the colonoscopy, and which symptoms should not wait.
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TL;DR
- A positive FIT means blood was detected in your stool. It is a signal to investigate, not a diagnosis.
- Most positive results are not cancer. Polyps, hemorrhoids, ulcers and other conditions can also cause bleeding.
- The standard next step is a colonoscopy, not a repeat stool test.
- Do not let it slide. A large study found that people who skipped the follow-up colonoscopy were about twice as likely to die of colorectal cancer.
- Rectal bleeding, unexplained weight loss, ongoing belly pain or a change in bowel habits deserve a medical visit whatever your FIT says.
Table of Contents
- What a positive FIT result actually means
- Does a positive FIT mean cancer?
- What else can cause blood on a FIT
- What to do after a positive FIT: step by step
- Why colonoscopy and not another stool test
- What happens at the follow-up colonoscopy
- What your colonoscopy results mean
- Symptoms that should not wait
- Why a single FIT is not the whole story
- Our perspective
- Book your follow-up colonoscopy in South Plainfield
- FAQ
- Sources
What a positive FIT result actually means
FIT stands for fecal immunochemical test. It is a home stool test that detects tiny amounts of human blood, usually blood you cannot see. A positive result (some labs and clinics say “abnormal”) means blood was present in the sample at or above the lab’s cutoff.
Why does blood show up at all? The Colorectal Cancer Alliance explains that blood vessels on the surface of larger polyps or cancers are fragile and can be damaged as stool passes, releasing a small amount of blood that is often invisible. That is exactly why the test is useful: it can flag a problem before you feel anything.
The test only says blood is there. It cannot say where it came from or why. That is the job of the follow-up exam.
What the cutoff means
Labs define “positive” using a concentration threshold. The U.S. Multi-Society Task Force, a group of gastroenterology organizations, favors a lower cutoff of 20 μg/g or less and notes it is used by a commonly available quantitative test in the U.S. A lower cutoff catches more findings, which also means more people get called back. That is part of why a positive result is common and usually not serious.
Does a positive FIT mean cancer?
No. Most people with a positive FIT do not have colorectal cancer. Numbers vary by program and population. BC Cancer, a provincial program in Canada, reports that about 10 to 15 percent of people screened with FIT get an abnormal result, and over 96% of those people turn out not to have cancer. U.S. programs differ in cutoff and population, so your own odds depend on your age, history and the test used.
That said, “not cancer” does not mean “nothing.” The same blood-detecting test that gives many false alarms also finds precancerous polyps and early cancers that cause no symptoms. A colonoscopy lets a doctor remove polyps before they can become cancer, which is the point of screening in the first place.
What else can cause blood on a FIT
The Colorectal Cancer Alliance lists several other sources of blood in stool besides cancers and polyps: ulcers, hemorrhoids, diverticulosis and inflammatory bowel disease. Diverticulosis means tiny pouches that form at weak spots in the colon wall.
That list matters in two ways:
- It explains why many positive results end with a reassuring colonoscopy.
- It means a colonoscopy can do more than rule cancer in or out. It can identify a treatable cause, such as hemorrhoids or colitis, that would otherwise go unaddressed.
If your symptoms point toward inflammation, such as ongoing diarrhea, cramping or urgency, you can read how doctors approach screening tests for IBD and what a calprotectin stool test adds.
What to do after a positive FIT: step by step
- Do not repeat the test and do not wait for it to “clear up.” The U.S. Multi-Society Task Force recommends colonoscopy when a FIT is positive, not a repeat FIT. A negative second test would not cancel out the first.
- Call your ordering provider or a gastroenterologist. Ask for a referral if you need one, and check what your insurance requires. A colonoscopy after a positive stool test is a diagnostic procedure, and coverage rules can differ from routine screening, so confirm with your plan before you book.
- Schedule the colonoscopy promptly. The VA recommends scheduling it within 60 days of an abnormal FIT, and contacting your medical team if you do not hear from them.
- Tell the doctor your history. Mention family history of colon cancer or polyps, blood thinners, iron supplements, diabetes, and any symptoms. These affect prep and sedation planning.
- Follow the bowel prep exactly. A clean colon is what lets the doctor see small polyps. Our guide to how to pick and prepare for colon cancer screening walks through it.
Why speed matters
In a National Cancer Institute analysis of 111,423 people with a positive FIT, those who did not get a follow-up colonoscopy were about twice as likely to die of colorectal cancer over 10 years as those who did.
Timing also matters on the scale of months. A VA study of more than 200,000 Veterans found that colonoscopy more than 13 months after an abnormal stool blood test was linked to up to 1.3 times higher odds of colorectal cancer, and advanced-stage odds were up to 1.7 times higher when colonoscopy was delayed beyond 16 months. The study’s authors noted that a long wait can allow polyps to progress, which can mean more aggressive treatment and less favorable outcomes.
The lesson is not to panic. It is to book the appointment now rather than “after the holidays.”
Many people never make the appointment
Follow-up is where the system often breaks down. The NCI notes that some U.S. screening programs struggle to ensure timely colonoscopy after a positive FIT, with completion rates as low as 50%. One study reported by Health.com found that 56% followed up within a year and 51% within six months, with insurance type and socioeconomic status influencing who did. If you have not heard from anyone about next steps, call and ask. Do not assume silence means the result was fine.
Why colonoscopy and not another stool test
A stool test predicts the possibility of a lesion. A colonoscopy lets the doctor see it. As gastroenterologist Dr. Dupinder Singh told Health.com, a colonoscopy helps visualize the lesion, remove it or take biopsies.
This holds for other stool-based tests too. A researcher quoted in a JAMA Network Open editorial said that if a stool-based test is positive, regardless of the type of test, a follow-up colonoscopy is recommended as soon as possible. If your positive result came from a stool DNA test rather than a FIT, our articles on what a positive result means and false positives cover that situation. Guidance summarized by the Merck Manual says patients with a positive fecal DNA-FIT test should get a follow-up colonoscopy within 6 months, though sooner is the better habit.
What happens at the follow-up colonoscopy
A colonoscopy uses a thin, flexible scope with a camera to examine the entire lining of the colon. You are sedated, and the exam is usually done as an outpatient procedure. You will need to complete the bowel prep the day before and arrange a ride home.
What the doctor does if something turns up:
- Polyps can usually be removed during the same procedure. The NCI says a follow-up colonoscopy can find cancer or precancerous polyps that doctors can remove, reducing future cancer risk.
- Suspicious areas can be biopsied and sent to a lab.
- Other findings, such as hemorrhoids, diverticula or inflamed tissue, are noted and addressed in your treatment plan.
The Florida Department of Health explains that if an abnormality is found, the provider may remove polyps or cancer during the procedure and will discuss whether further tests or treatments are needed afterward.
For a closer look at the procedure itself, see our page on colonoscopy at our South Plainfield practice.
What your colonoscopy results mean
There are three broad outcomes.
| Finding | What it usually means | What often comes next |
|---|---|---|
| Normal colon | The blood likely came from a minor source such as a hemorrhoid | Your doctor sets your next screening interval |
| Polyps removed | A likely source of the blood has been found and taken out | Pathology report, then a surveillance schedule |
| Cancer or other disease found | A diagnosis was reached early enough to act on | Treatment planning, or targeted care for the specific condition |
The VA says that after the colonoscopy your provider will make recommendations based on what it shows. If cancer is detected, the NCI notes treatment is usually the next step.
To make sense of the paperwork afterward, our guide on how to read your colonoscopy report explains the terms. How often you return depends on what was found; see colonoscopy frequency for typical intervals.
If the colonoscopy is normal
A normal colonoscopy after a positive FIT is a common and good outcome. The Task Force suggests that without iron-deficiency anemia or signs or symptoms of upper gastrointestinal problems, a positive FIT with a negative colonoscopy should not prompt upper GI evaluation. If you do have symptoms such as persistent heartburn or unexplained anemia, tell your doctor, because that changes the picture. Reflux symptoms are something we treat directly through GERD and acid reflux care.
Symptoms that should not wait
A positive FIT is one signal. Symptoms are another, and they count whatever your stool test says. The American College of Surgeons says blood in the stool is not always cancer but is never normal. It lists these early warning signs: blood in the stool or toilet water, thin or pencil-shaped stool, ongoing belly pain or cramping, unexplained weight loss, unusual tiredness from low iron, and anemia on a blood test.
The same guidance advises that if you have rectal bleeding, especially with a change in bowel habits, unexplained weight loss or persistent abdominal pain, you should ask your provider whether a colonoscopy is needed, even if you are younger than 45. If you are bleeding heavily, feel faint, or have severe abdominal pain, seek urgent or emergency care rather than waiting for a scheduled appointment.
Why a single FIT is not the whole story
FIT is a good screening tool, not a perfect one. The Task Force states that one-time FIT is approximately 80% sensitive for cancer and 20% to 30% for advanced neoplasia, and recommends repeated testing, including annual FIT. For people who prefer a home test, that makes yearly testing the way it works best. It also means a positive result deserves a response, because the test is doing what it was designed to do.
Other screening options exist, and our overview of types of digestive screenings and stool tests explained lay them out. The ACG 2021 guidelines, as summarized by the Merck Manual, list colonoscopy every 10 years or annual FIT as the preferred screening tests. Once you have a positive FIT, though, you have moved from screening to diagnosis, and colonoscopy is the test that answers the question.
Our perspective
A positive FIT is the moment screening has worked. It has pointed to a place worth looking, and the colonoscopy is how we look. What we see in practice is that people are not afraid of the procedure so much as the unknown. They wonder what the result means, whether it is cancer, and how soon they have to act. We think the best care answers those questions plainly, in a language the patient is comfortable with. That is why Dr. Parikh, a board-certified, fellowship-trained gastroenterologist, speaks English, Gujarati, Hindi and Spanish. Our approach is to take the result seriously without alarm. We review your symptoms and history, explain the colonoscopy and the prep step by step, and tailor the plan to you. If a polyp is found, the goal is to address it. If a cause such as hemorrhoids, reflux or IBD is found, we can continue to manage it with you through follow-up care. The single most useful thing you can do is book the colonoscopy. Precision Digestive Health
Book your follow-up colonoscopy in South Plainfield
If you live in or near South Plainfield, NJ, Dr. Meet Parikh can evaluate your positive FIT, perform your colonoscopy, and guide you through whatever the results show. Our colon cancer screening services cover the full path from the first conversation to follow-up care.
To schedule, visit our services page or contact the office through precisiondigestive.com. Bring your FIT result and a list of your medications. Because we bill insurance and also accept self-pay patients, ask our staff about coverage when you call.
FAQ
Can you have a positive FIT test and not have cancer?
Yes, and most people do not have cancer. Blood in the stool can come from polyps, hemorrhoids, ulcers, diverticulosis or inflammatory bowel disease. A colonoscopy is how doctors find the actual source and rule cancer in or out.
Should I repeat the FIT test to be sure?
No. Guidance from the U.S. Multi-Society Task Force is to proceed to colonoscopy after a positive FIT, not to repeat the test. A second negative result would not erase the first one.
How soon should I get a colonoscopy after a positive FIT?
As soon as you reasonably can. The VA recommends scheduling it within 60 days, and studies link longer delays to worse outcomes. If you have not heard from your provider about scheduling, call them.
What if my colonoscopy finds nothing?
That is a common result and a good one. Your doctor will set your next screening interval and may look into other causes if you have ongoing symptoms or anemia. Keep reporting new bleeding or changes in bowel habits.
Is it a positive FIT if I only saw a little blood or none at all?
Yes. FIT is designed to detect blood you cannot see. A positive result without visible bleeding is normal and is the reason the test exists.
Sources
- Fecal Immunochemical Test (FIT), Colorectal Cancer Alliance
- Understanding Your Results, BC Cancer
- FIT Kit for Colorectal Cancer Screening, Veterans Affairs
- Follow-Up Colonoscopy after Positive FIT Test, National Cancer Institute
- Fecal immunochemical testing (FIT) to screen for colorectal neoplasia, U.S. Multi-Society Task Force
- Study: Delaying colonoscopy following abnormal stool test, VA Research
- Study: Delaying colonoscopy following abnormal stool test, VA News
- Study: Many People Don’t Follow Up With a Colonoscopy, Health.com
- Critical gap in colorectal cancer screening process, ecancer
- Colorectal Cancer Screening, Merck Manual Professional Edition
- Colorectal Cancer, Florida Department of Health
- Know the Symptoms of Colorectal Cancer, American College of Surgeons
