Occult Blood (Fecal Occult Blood/FOB)
This stool test detects hidden (occult) blood that is not visible to the naked eye. It is a key screening tool for colorectal cancer and can also indicate gastrointestinal bleeding from other sources.
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- Includes Doctor Consultation
- Physician-reviewed
- Same Day Collection
24 hours
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Stool
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What the Occult Blood (Fecal Occult Blood/FOB) test tells you
Blood coming from the bowel is not always visible. Small, intermittent losses from a polyp, an ulcer or an early tumour mix into the stool and change nothing you can see, yet over months they can quietly drain the body's iron stores. A faecal occult blood test looks for that hidden blood chemically, using a sample you collect at home.
The modern immunochemical version, often called FIT or iFOBT, uses antibodies that recognise human haemoglobin specifically. That specificity matters in two ways. Red meat and peroxidase-rich vegetables no longer interfere as they did with the older guaiac method, so dietary restriction is generally unnecessary. And blood from higher up the digestive tract, where haemoglobin is largely broken down before it reaches the stool, is less likely to register, which weights the test towards bleeding from the colon and rectum.
Its central role is bowel cancer screening, alongside investigating unexplained anaemia. Colon cancers usually begin as polyps that bleed occasionally long before causing symptoms, and finding them at that stage changes outcomes substantially. Two honest points follow. A positive result has many possible causes, including entirely benign ones such as haemorrhoids, and it is normally followed by direct examination of the bowel, usually colonoscopy, rather than by simply repeating the stool test. And because bleeding is intermittent, a single negative result does not exclude a source, which is why screening is repeated at the interval your doctor advises rather than done once.
Recommended as a routine colorectal cancer screening tool for adults over 45, and to investigate iron deficiency anaemia or suspected GI bleeding.
- Bowel cancer screening
The main use. It detects bleeding from polyps and early cancers at a stage when they cause no symptoms and treatment works best.
- Explaining iron deficiency
When iron stores are low without an obvious reason, slow bleeding from the gut is one of the possibilities that has to be looked for.
- A non-invasive first step
A stool sample collected at home helps identify who needs a colonoscopy, sparing the procedure for people unlikely to benefit from it.
- Investigating gut symptoms
Alongside a change in bowel habit or abdominal discomfort, it adds objective evidence of bleeding that symptoms alone cannot give.
Reasons your doctor may request the Occult Blood (Fecal Occult Blood/FOB) test
Your doctor may order this test for any of the reasons below. Some are routine checks, others follow specific symptoms or an earlier result.
Routine bowel cancer screening
- Routine bowel cancer screening from the age your doctor recommends, repeated at the advised interval.
Anaemia & bowel symptoms
- Iron deficiency anaemia without an obvious explanation.
- A persistent change in bowel habit, or unexplained abdominal pain or weight loss.
Family history & polyp follow-up
- A family history of colorectal cancer or polyps, as part of a screening plan set by your doctor.
- Surveillance after a polyp has been removed, where your doctor includes it in follow-up.
A Positive result means human haemoglobin was detected in your stool sample: bleeding somewhere in the bowel that you cannot see. It identifies bleeding, not its cause, and most positive tests turn out to have a benign explanation such as haemorrhoids or an anal fissure. Polyps, inflammatory bowel disease, diverticular disease and ulcers linked to aspirin or anti-inflammatory painkillers can all produce one, as can menstruation or bleeding gums. A positive screen is normally followed by direct examination of the bowel, not by repeating the stool test. A Negative result means no blood was detected in that particular sample. Because bleeding from polyps and tumours comes and goes, one negative test covers one round of screening rather than settling the question, which is why it is repeated at the interval your doctor advises. Your doctor reads it with your symptoms and blood count.
Medically reviewed by Dr Nirupama Sabhapathy
This test is reported descriptively rather than on a numeric scale: each finding below explains what your report may say.
No blood detected in the sample.
Blood detected: further evaluation is usually advised. Consult your physician.
Ranges are a guide: your physician interprets your result alongside your symptoms and history.
What a higher result can point to
- Colorectal polyps, which commonly bleed on and off long before causing symptoms.
- Colorectal cancer, including early lesions that produce no symptoms at all.
- Haemorrhoids and anal fissures, among the commonest and most benign reasons for a positive result.
- Inflammatory bowel disease, diverticular disease, or infectious colitis.
- Ulcers or erosions in the stomach and small bowel, particularly with anti-inflammatory painkillers or aspirin.
- Blood entering the sample from menstruation, or from bleeding gums or nose.
These are possibilities, not diagnoses. A single value outside the reference range is interpreted alongside your symptoms, history and other tests: your doctor decides what it means for you.
What this test cannot tell you
- A positive result identifies bleeding, not its cause, and most positive tests turn out to be due to benign conditions such as haemorrhoids.
- Bleeding from polyps and tumours is intermittent, so a single negative test does not exclude one, which is why screening is repeated at intervals.
- Immunochemical tests target human haemoglobin from the lower bowel and are less sensitive to bleeding from the stomach and upper small intestine.
- A negative result carries no meaning beyond the absence of detectable blood in that particular sample.
Collecting your sample safely
- No needle is involved, and collecting the sample carries no physical risk.
- Wash your hands well with soap and water afterwards, since stool can carry infection.
- Keep the sample clear of urine and toilet water, close the container firmly and keep it cool until it is collected.
- 1The test finds blood you cannot see; it does not find cancer directly.
- 2A positive result is normally followed by direct examination of the bowel, usually colonoscopy, not by repeating the stool test.
- 3Most positive results turn out to have a benign cause, most often haemorrhoids.
- 4Bleeding comes and goes, so one negative test covers one round of screening rather than settling the question for good.
- 5Immunochemical versions recognise human haemoglobin specifically, so dietary restriction is generally not required.
Occult Blood (Fecal Occult Blood/FOB) also comes in these focused packages, which pair it with the tests usually read alongside it.
- Stool StudiesCalprotectin Qualitative
Faecal calprotectin is a protein released by inflamed intestinal tissue. This stool test helps distinguish inflammatory bowel disease (IBD) from…
275View - HaematologyHemoglobin (Hb)
Haemoglobin is the oxygen-carrying protein in red blood cells. This test measures haemoglobin levels to detect anaemia, polycythemia, or monitor…
25View - BiochemistryFerritin
Ferritin reflects your body's iron stores. Low levels indicate iron deficiency (even before anaemia develops), while very high levels may suggest…
55View - Tumour MarkersCarcino Embryonic Antigen (CEA)
CEA is a protein that can be elevated in certain cancers, especially colorectal cancer. This blood test is primarily used to monitor cancer treatment…
80View
Frequently Asked Questions
Everything you need to know about the Occult Blood (Fecal Occult Blood/FOB) test. Can't find what you're looking for?
Talk to our team→It is recommended as a routine colorectal cancer screening test for adults over 45, because polyps and early cancers can bleed long before they cause symptoms. Doctors also use it to investigate iron deficiency anaemia or suspected bleeding from the bowel. Your doctor advises how often to repeat it, since one negative test covers one round of screening.
They do different jobs. The stool test finds blood you cannot see, not cancer directly, and because bleeding from polyps and tumours comes and goes it is repeated at intervals. A colonoscopy looks at the bowel lining directly and is the usual next step after a positive result. The stool test is a simple screen that decides who needs that direct look.
They can make a positive result more likely, because aspirin and anti-inflammatory painkillers can cause ulcers or erosions that bleed, and blood thinners make any bleeding more noticeable. They do not usually mean cancelling the test, and you should not stop them without your doctor's advice. Tell your doctor you take them, since it changes how a positive result is read.
Yes. Blood from menstruation, visibly bleeding haemorrhoids, nosebleeds or bleeding gums can register in the sample. Postpone collection until these have settled. Haemorrhoids and anal fissures are among the commonest and most benign reasons for a positive result, but the source still needs to be confirmed by your doctor rather than assumed.
Collect it at home in the container provided, taking material from the passed stool and keeping it clear of urine and of water from the toilet bowl. Keep the sample cool and return it promptly. If you are menstruating or have bleeding haemorrhoids, wait until that has settled before collecting.
No. It means blood was detected in the sample. Haemorrhoids, fissures, polyps, inflammation and ulcers all produce the same finding, and benign causes are far more common than cancer. It does mean the source needs to be identified, and your doctor will usually arrange a colonoscopy to look directly.
Not for the immunochemical test used today, which recognises human haemoglobin specifically and ignores blood or plant peroxidases from food. The older guaiac method did require avoiding red meat and certain vegetables, so check which test you are having if you are unsure.
Less reliably. Haemoglobin from the stomach and upper small bowel is largely digested before it reaches the stool, so immunochemical tests are weighted towards bleeding from the colon and rectum. Bleeding higher up is usually investigated in other ways, such as gastroscopy.
For this round it is reassuring, but not permanently. Polyps and tumours bleed on and off rather than constantly, so a single sample can miss one that is present. That is exactly why screening is repeated at set intervals rather than done once.
No. No fasting is needed, and with the immunochemical test used for bowel screening you do not need to avoid red meat or particular vegetables. Keep the sample cool and return it promptly after collection.
The faecal occult blood test is AED 60, including a physician-reviewed report, with results usually within 24 hours. Home collection anywhere in Dubai is free when your order reaches AED 300 or includes a package; below that, a AED 100 home collection fee applies (AED 50 for a lab walk-in).