Stool Test

A stool test is a diagnostic tool that healthcare providers use to find out why you’re having stomach issues. This test can detect bacteria, viruses and other germs in your poop that can make you sick. Healthcare providers use stool tests to help diagnose gastrointestinal diseases and colon cancer.


What is a stool test?

A stool test looks for pathogens (bacteria, viruses, parasites) in your poop that can make you sick. Stool tests can also look for other signs, like hidden blood, that signal something’s wrong. Healthcare providers can use stool tests to check for a wide range of gastrointestinal (GI) issues, including infections and cancers.

Your healthcare provider might recommend a stool test if you develop symptoms like:

  • Blood in your poop.
  • Mucus in your poop.
  • Diarrhea (loose poop) that’s lasted for more than three days.
  • Stomach pain or cramping.
  • Nausea or vomiting that lasts days.
  • Fever.

What does a stool test check for?

Stool tests can check for several different gastrointestinal conditions, including:

Types of stool tests

There are different types of stool tests. Your provider will choose the best test based on your symptoms:

  1. Fecal occult blood test (FOBT): This type of stool test looks for traces of blood in your poop. A positive result means you have bleeding somewhere in your digestive tract.
  2. FIT-DNA test: Like the FOBT, this stool test detects tiny amounts of blood in your poop. But it also looks for altered DNA that could indicate precancerous or cancerous conditions. (Note: “FIT” stands for fecal immunochemical test.)
  3. Tests for infection: Providers can run these tests in a few different ways. But all these tests look for germs in your stool by either growing them, looking for them under the microscope or looking for germ DNA.

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Test Details

How do I prepare for a stool test?

You may not need to make special preparations before your stool test. But there are some instances where your provider may ask you to follow certain instructions (like stopping certain medications or avoiding certain types of foods). These instructions will depend on the test you take and can be different for different people. Be sure to ask your healthcare provider if you need to do anything differently before your stool test.

How do I collect my stool sample?

In most cases, you’ll be able to collect your stool sample at home. Your provider will give you everything you’ll need, including a specimen container with your name and birthdate.

Your provider will give you specific instructions, but here are some general steps for collecting your stool sample:

  1. If you need to pee, do it before you set up for your stool test. You’ll want to avoid mixing pee with your poop sample because it can interfere with the results.
  2. Place something in the toilet to catch your poop. Your provider may give you a tray or container for this purpose. You can also place a piece of plastic wrap between the toilet seat and the rim of the toilet bowl or any clean container. (Avoid the plastic wrap method if you have loose or watery poop.)
  3. Don’t let your poop touch the inside of the toilet bowl. This can contaminate your sample.
  4. Use a plastic scoop to place the sample inside the specimen container. Your provider will tell you how much poop they need, or the container will have a fill line. (If your provider didn’t give you a plastic scoop, you can use a disposable spoon.)
  5. Close the specimen container immediately and secure the lid tightly.
  6. If there’s remaining poop, carefully tip it into the toilet.
  7. Put everything you used to collect the poop into a plastic bag, tie it up tightly and place it in the waste bin.
  8. Wash your hands thoroughly with antibacterial soap and running water.
  9. Deliver your specimen to the lab or your provider’s office as soon as possible. If you need to wait for any reason, you can keep your sample in the refrigerator for a short time. If you don’t return your sample within 24 hours, your stool sample probably won’t be tested.

Be sure to read any instructions your healthcare provider gives you. They may have more specific guidelines for collecting your specimen.


Results and Follow-Up

How long does a stool test take?

You’ll likely get your stool test results back in one to three days. But it could take longer depending on what your provider tests for.

How will the lab test my sample?

It depends on the type of test. For some stool tests, providers smear the stool onto a testing card. For others, they place the stool on a glass slide and look at it under the microscope. They may also put the stool on a plate that has food for the germs to grow so they can see them. Sometimes the germs can be hard to see, so providers place them in a machine that copies their DNA over and over again.


What do the results mean?

Stool test results can be positive or negative. A negative result means your poop looks typical, and the lab didn’t find any signs of disease like blood or germs. If your stool tests positive for a germ, the test result may also give you the name of the bug.

If the results are positive, what are the next steps?

If your stool tests positive, the pathologist will tell your healthcare provider what kinds of germs or pathogens they found. They’ll also tell your provider if there are other signs of infection, like an abnormal amount of blood or fat in your stool. This information will help your provider find the cause of your symptoms and recommend appropriate treatment.

If your results suggest a cancerous growth, your provider will refer you to an oncologist for further testing and treatment.

Additional Common Questions

Is a stool test as good as a colonoscopy?

Stool tests can give healthcare providers lots of helpful information, but sometimes it’s too early to be able to detect changes in your intestine through stool. In such cases, especially if your stool tests are negative and your symptoms continue, your provider may suggest a colonoscopy. A colonoscopy uses a long tube with a light and a camera so that your provider can get a direct view of what’s happening inside your body. It can help them find growths when they’re still small and easier to remove.

A note from Cleveland Clinic

Getting a stool test isn’t anyone’s idea of fun. And it’s normal to feel a little scared or uneasy if you’ve never had one before. But don’t let apprehension stand in your way. If you think something isn’t quite right, let your provider know. A simple stool test can tell your healthcare provider a lot about what’s causing your gastrointestinal issues. By finding out what pathogens are in your poop, your provider can give you the most accurate diagnosis and the most effective treatment.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 08/24/2023.

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