What Does A Stool Test Show?

A stool test can detect many things significant to health: anything from parasite infection to signs of cancer, yeast or bacterial overgrowth, or pathogenic bacteria like C. difficile, Campylobacter and certain strains of E. coli.

While your GP might give you a stool test to find out if you could have Inflammatory Bowel Disease, a Registered Nutritional Therapist or Functional Medicine Practitioner might recommend one to check out the health of your microbiome.

So, what your stool sample detects depends on which stool test you have.

What does a UK stool sample detect?

Generally, there are two types of stool tests used in the UK: the type doctors use to detect serious conditions, and the type holistic practitioners use to look at your microbiome and a range of gut health markers.

Doctors usually ask their patients for a stool sample to check for diseases like cancer, Crohn’s disease or ulcerative colitis. If you go to your doctor with IBS symptoms like diarrhoea, constipation or bloating, or if you’ve been passing mucus or blood in your bowel movements, they could ask you to do a stool sample to rule out these conditions.

There are many other conditions that your doctor might want to check for with a stool test, so if you’ve been asked to do a stool sample, they’re the best person to ask.

If you’re doing a stool test through a holistic health provider—like Healthpath—or a practitioner like a Registered Nutritional Therapist, acupuncturist or chiropractor, for instance, it’s likely to be something we call a Gut Health Test. As the name suggests, Gut Health Tests look at the health of your gut. They don’t diagnose any serious conditions.

Find a test that's right for you.

View our gut health tests

What can be picked up in a stool sample? 

Stool samples usually go to a laboratory where technicians will examine the stool. Some conditions will be detectable without a microscope, for example some species of worms are very clear to see without any technology. Other species of worms, however, are smaller and harder to see.

Again, there are many different kinds of stool tests to detect many different conditions. Below you can find a list of some of the most common conditions your doctor would look for with a stool test.

Which diseases can be detected in a stool sample? 

Colon cancer

Two types of stool tests are used as screening tools for colorectal cancer, or the precancerous cells that can lead to cancer. The older test finds hidden blood in the stool. A newer test looks at DNA in the stool for evidence of colorectal cancer. 

However, if either the stool DNA test or the hemoccult test is positive, you will still need a colonoscopy to find and remove the precancerous or cancerous lesion.

Inflammatory bowel disease

A common initial test for IBD measures calprotectin levels in stool. Calprotectin is a protein that is found in white blood cells and it has strong antibacterial and antifungal properties.

Calprotectin rises when inflammation occurs (whatever the cause of that may be). The concentration of calprotectin relates directly to the severity of the inflammation: the more severe your IBD, the higher your calprotectin levels will be.

Fat malabsorption

Stool tests can detect abnormally high amounts of fat, which are a sign that you’re not digesting and absorbing fat in your food properly. There are many different reasons for this: knowing that you don’t absorb fat is different to knowing why, so you’ll need further tests if this happens to you.

Pancreatic insufficiency

To look for pancreatic insufficiency, you can get a test that measures elastase in your stool. Elastase is an enzyme made by special tissue in the pancreas, an organ in your upper abdomen. Elastase helps break down fats, proteins, and carbohydrates after you eat. It’s an important part of digestion.

If your pancreas is healthy, there’ll be enough elastase in your stool. If little or no elastase is found in your stool, it can indicate pancreatic insufficiency. 

Pancreatic insufficiency can cause a number of health problems, because it leads to malabsorption and malnutrition. When you can’t digest or absorb the nutrients in your food, your body doesn’t have the building blocks it needs to be healthy.

Speak to a gut health expert.


Which infections can be found in a stool sample? 

There are three main infections that doctors in the UK look for in stool samples: pathogenic bacteria, parasites and worms.

Pathogenic bacteria

The most common pathogenic bacteria include:

  • Salmonella, often found in raw eggs and raw poultry
  • Shigella, from contaminated food and water
  • Campylobacter, from raw or undercooked poultry: the most common cause of bacterial diarrhoea in the UK
  • Escherichia coli 0157:H7 (other strains of E. coli are considered ‘normal’) found in raw or undercooked beef


Stools can also contain parasites or their eggs. These are produced by many tiny organisms such as Giardia or Blastocystis.

Blastocystis infections are commonly found in the UK. We can’t be sure whether it causes disease or not: millions of people in the developing world harbour Blastocystis with no symptoms at all, but many people in the UK get diarrhoea with a Blastocystis infection [Source: PubMed].

Giardia is not quite as common as Blastocystis in the UK, and can cause more severe symptoms. However, doctors and specialists still don’t agree on whether or not we need to eradicate it with antibiotics. Some people live their whole lives with Giardia with no problems, while others have uncomfortable symptoms, like stomach pain, fatigue, greasy stools and wind [Source: PubMed]. 

It could be that our immune systems in the developed world haven’t been ‘trained’ as they should: we evolved over millions of years living outside, and parasites were unavoidable, as they still are in some parts of the world.

Today, we live very clean lives and our immune systems can overreact to things that wouldn’t have been a problem in the past: this is a big factor in the rise of autoimmune diseases [Source: PubMed].

Our Gut Health Tests here at Healthpath pick up both Giardia and Blastocystis. If your results come back positive for either of these parasites, we recommend you tell your doctor before deciding what to do next.

Worms (Helminths)

You can pick up worms in a variety of ways: if you’ve travelled to a tropical country, for example, or work with children in a daycare centre.

Your doctor may test for them by looking at your stool, or sending it away to a laboratory. 

Symptoms of a worm infection include:

  • abdominal pain
  • diarrhoea, nausea, or vomiting
  • gas/bloating
  • fatigue
  • unexplained weight loss
  • abdominal pain or tenderness

Another test is the “Scotch tape” test, where your doctor will put sticky tape around your anus to look for evidence of pinworm eggs.

What can be detected in an NHS stool test? 

NHS stool tests are used to diagnose or rule out serious diseases or infections, as we’ve outlined above.

A Healthpath stool test is different to an NHS stool test.

Healthpath stool tests are comprehensive stool tests. Many UK companies now offer comprehensive stool tests, and they call them all different names. Ours are called Gut Health Tests.

Comprehensive stool tests not only look at a broad range of microbes in your gut: bacteria, yeasts, archaea and parasites, but functional markers too, such as:

  • Calprotectin, which indicates gut inflammation (the NHS also uses this marker, as we explained above)
  • Secretory IgA, which measures immune activity in the gut (Source: NCBI)

Find a test that's right for you.

View our gut health tests

Why get a Healthpath Gut Health Test?

Our Gut Health Tests don’t diagnose any serious conditions, but you should see your GP if, for example, your calprotectin is out of range. Your report will tell you all you need to know about next steps if that happens.

Our stool tests give you insight into your overall gut health. If you’re suffering from uncomfortable gut symptoms, the information on the types and levels of microbes in your gut along with the functional markers can help you to understand what’s going on in your gut.

All our Gut Health Tests come with bespoke, professional support: a supplement schedule, diet plan and lifestyle recommendations to target any issues or imbalances that show up in your results. Our Registered Nutritional Therapists and Functional Medicine Practitioners—who create all our protocols—base all their advice on the latest research.

Your gut is the seat of your health

Your gut does so much more than digest your food.

Because so much goes on in your gut that affects the rest of your body, imbalances in your gut can cause problems in almost any area of your health. Recent research has revealed links between the following conditions and your gut health:

Key takeaways

  • There are two main reasons anyone gets a stool test. The usual reason is that your doctor has recommended you get one so they can diagnose or rule out a serious condition or infection.
  • However, more and more people are exploring their gut health through stool testing too.
  • Rather than looking for evidence of anything serious, gut health tests take a deep dive into the communities of microbes living in your gut, and examine other markers of gut health like your levels of inflammation and digestive enzymes.
  • Your gut health and the health of the rest of your body and mind is intricately connected. If you want to get a window into the goings on of your gut, a Gut Health Test is a great idea.
  • If you want to check for serious disease or infection, speak to your doctor.


Alexandra Falconer MA (Dist) DipCNM mBANT is a Registered Nutritional Therapist specialising in IBS and related conditions. A graduate of Brighton’s College of Naturopathic Medicine, she is committed to fighting the root causes of chronic illness and bringing functional medicine to everyone who needs it.

Before her natural health career, Alex was a journalist and copywriter. She continues to write for magazines and media agencies, and now combines her two great passions—writing and health—by creating content that empowers people to claim their right to a healthy body and mind.


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