Home Stool Test (FIT): Results and What to Expect

A FIT kit is a home test that looks for blood in a small sample of poo. It is used in bowel cancer screening, which is meant for people who have no symptoms.

What the test measures

FIT stands for faecal immunochemical test. The US National Cancer Institute describes it as a check for occult, or hidden, blood. The US Preventive Services Task Force (USPSTF) notes that FIT finds blood with antibodies, while the guaiac test (gFOBT) uses a chemical. The USPSTF adds that gFOBT needs some diet and medication restrictions and three separate bowel movements, whereas FIT needs no such restrictions and can use a single stool sample. Your own kit’s instructions still come first.

Who is offered a kit

Programs differ by country.

• England: the NHS offers the home test to people aged 50 to 74 every 2 years. People 75 and over can ask for one by calling the helpline on 0800 707 6060.
• United States: the USPSTF recommends screening adults at average risk without symptoms from 45 to 75, and selectively from 76 to 85. Yearly FIT is one option; others include sDNA-FIT every 1 to 3 years and colonoscopy every 10 years.
• South Korea: the national program offers men and women aged 50 and over a fecal occult blood test once a year.

Because the benefit builds up over repeated rounds, the USPSTF stresses keeping to the testing interval.

Symptoms change the plan

Screening is for people without symptoms. The NHS lists signs that should send you to a GP rather than a screening kit: changes in your poo that are not usual for you (softer poo, diarrhoea or constipation), pooing more or less often than usual, blood in your poo (red or black), bleeding from your bottom, often feeling you need to poo even after going, tummy pain, a lump in your tummy, bloating, losing weight without trying, and feeling very tired or short of breath.

These symptoms are common and can have other causes, and a GP may give you a FIT kit to check for bleeding. The NHS advises an urgent GP appointment or a call to 111 if your poo is black or dark red or you have bloody diarrhoea, and 999 or A&E if bleeding from your bottom will not stop or you pass a lot of blood or large clots.

Collecting the sample

Follow your kit’s leaflet. The NHS steps run roughly like this: write the date on the sample bottle, catch the poo in a clean container so it does not touch toilet water, scrape the stick along the poo until the grooves are covered (only a small amount is needed), close the lid tightly, wash your hands, and post the kit as soon as you can. If you have had bowel surgery or have a stoma and are unsure whether you can use the kit, the NHS suggests calling the helpline.

Reading your result

The NHS says results usually arrive within 2 weeks of sending your sample, though it can take longer. Sometimes you are asked to repeat the test to make sure it was done properly.

“No further tests needed” means no blood was found, and most people get this result. Even so, the NHS says it does not always mean you do not have bowel cancer, so know the symptoms above.

“Further tests needed” means blood was found. You are offered an appointment with a specialist nurse and usually a colonoscopy. Blood does not always mean cancer, and anal fissures and bowel polyps are more common causes. The USPSTF says a positive stool test needs a follow-up colonoscopy for the benefits of screening to be achieved, and both the USPSTF and NCI note that false positives and false negatives can happen. In Korea’s national program, a positive result leads to a colonoscopy, with a tissue diagnosis if needed.

How bellySignal helps

bellySignal does not test for blood or replace screening, but it keeps a dated record you can bring to an appointment. You can log Bristol stool type 1 to 7, stool color, blood or mucus, and notes such as the day you posted your kit or got a result letter. Entries sit on a dated timeline, so you can see when you first logged a change and what came before and after it. You can export a PDF summary of the last 90 days to show a doctor.

Your diary is stored on your device, and no account is required. Optional login, health platform sync, and export are available. Selected health values, including stool type, symptoms and manually entered weight, are also sent to PostHog, which is enabled by default. The analytics switch controls PostHog only. Firebase Analytics receives usage events without those health values and remains active. Privacy policy. Get bellySignal on Google Play.

This article is general information and not medical advice. Follow your kit instructions and your screening provider, and talk to a doctor about symptoms or results.