Stool Tests

Overview

What Is a Stool Test and Why Is It Done?

A stool test checks a sample of stool (feces or poop) for things like germs and blood. Testing a stool sample can help doctors find out what's going on when someone has a problem in the stomach, intestines, rectum (where poop is stored until it leaves through the anus), or other parts of the digestive system.

Most of the time, doctors order a stool test to check someone’s intestines for an infection by bacteria, viruses, or parasites (organisms that need to live on or in a person, animal, or plant to survive).

Unlike most other lab tests, parents might need to collect the stool sample for the test. The doctor or lab will give instructions on how to do this.

Top Things to Know

• A stool test checks poop for things like bacteria, viruses, parasites, blood, and fat.
• Doctors order the test if there might be a problem with a child's digestive system.
• Kids may need to stop taking certain medicines or stop eating some foods before the test.
• Your doctor can explain what the results mean for your child.

What Can a Stool Test Show?

Stool tests can help doctors find many different kinds of problems, like:

• Infections of the digestive system by some types of bacteria, viruses, or parasites.
• Digestive problems, like trouble absorbing some kinds of sugars, fats, or nutrients. Some stool tests check for what the poop contains, like fat. Normally, the intestines absorb fat, so there’s very little fat in poop. But in some digestive disorders, like celiac disease, fat isn’t well absorbed and stays in the poop.
• Bleeding inside the digestive system.
• Inflammation (for instance, from a milk protein allergy in infants or inflammatory bowel disease).

What Are Some Types of Stool Tests?

Common stool tests that doctors order for kids include:

• Bacteria culture to check for bacteria that might be causing an infection.
• C. Difficile toxin to look for toxins (harmful substances) made by a kind of bacterium that can cause diarrhea and stomach pain, sometimes after taking antibiotics.
• Fecal occult blood to check for tiny amounts of blood in the poop that can’t be seen but might be a sign of a problem in the digestive system.
• Giardia to look for a parasite that can cause diarrhea, belly pain, and nausea.
• H. Pylori antigen to check for a type of bacterium that can live in the stomach and cause peptic ulcers (sores in the lining of the stomach, small intestine, or esophagus).
• Ova and parasites to look for parasites or their eggs (ova) and help find infections that can cause problems like diarrhea and blood or mucus in the poop.

Getting a Stool Test

How Can I Help My Child Prepare for a Stool Test?

Collecting a stool sample is painless. Tell your child that it won't hurt but it must be done carefully. After your child poops, the stool will need to be put into the provided container. Kids who are old enough might be able to get a sample alone to avoid embarrassment. Go over the directions with your child so they can do this properly.

Sometimes only one stool sample is needed but other times, samples are needed from different bowel movements. Your doctor will let you know if this is the case.

How Long Do Stool Test Results Take?

Depending on the kind of stool test, results can be back in 24–48 hours or take 3–7 days.

What Do Stool Test Results Mean?

Lots of things, like food and medicine, can change the results of a stool test. Your doctor will explain what the results of the test mean for your child.

If you have questions about stool tests, talk with your doctor.