Stool Test: Bacteria Culture

Stool Test: Bacteria Culture

What It Is

A stool (feces) sample can provide doctors with valuable information about what's going on when a child has a problem in the stomach, intestines, or other part of the gastrointestinal (GI) system.

A stool culture helps the doctor determine if there's a bacterial infection in the intestines. A technician places small stool samples in sterile plastic dishes containing nutrients that encourage the growth of certain bacteria. The targeted bacteria will only grow if they're already present in the stool sample. If bacterial colonies form, the technician evaluates them using a microscope and chemical tests to identify the organism.

Why It's Done

A doctor may request a stool culture to look for illness-causing bacteria such as:

On occasion some other illness-causing bacteria may be noted.

The stool culture might be ordered if your child has diarrhea for several days or has bloody diarrhea, especially if there's been an outbreak of foodborne illness in your community, your child has recently eaten undercooked meat or eggs or unpasteurized milk, or your child has recently traveled to certain places outside the United States.

Preparation

Unlike most other lab tests, a stool sample is usually collected by parents at home, not by health care professionals at a hospital or clinic. No special preparation is required, but tell your doctor if your child has recently taken antibiotics.

Procedure

The doctor or hospital laboratory will usually provide written instructions on how to collect a stool sample. If instructions aren't provided, here are tips for collecting a stool sample from your child:

What to Expect

When the sample arrives at the laboratory, a technician smears stool samples on a growth-encouraging substance inside sterile plates. These plates are each kept at a temperature that ensures the quickest growth of targeted bacteria.

If no bacterial colonies form, the test is negative, meaning that there's no sign of a bacterial infection. But if bacterial colonies do form, the technician examines them under a microscope and may perform chemical tests to identify them more specifically.

Getting the Results

In general, the result of the stool culture is reported within 24 to 48 hours.

Risks

No risks are associated with collecting stool samples.

Helping Your Child

Collecting a stool sample is painless. Tell your child that collecting the stool won't hurt, but it has to be done carefully. A child who's old enough might be able to collect the sample alone to avoid embarrassment. Tell your child how to do this properly.

If You Have Questions

If you have questions about the stool culture, speak with your doctor.

Reviewed by: Steven Dowshen, MD
Date reviewed: September 2011





Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.

© 1995-2014 The Nemours Foundation/KidsHealth. All rights reserved.





Bookmark and Share

Related Resources
OrganizationAmerican Medical Association (AMA) The AMA has made a commitment to medicine by making doctors more accessible to their patients. Contact the AMA at: American Medical Association
515 N. State St.
Chicago, IL 60610
(312) 464-5000
OrganizationCenters for Disease Control and Prevention (CDC) The mission of the CDC is to promote health and quality of life by preventing and controlling disease, injury, and disability. Call: (800) CDC-INFO
OrganizationAmerican Academy of Pediatrics (AAP) The AAP is committed to the health and well-being of infants, adolescents, and young adults. The website offers news articles and tips on health for families.
Related Articles
Stool Tests Your child's doctor may order a stool collection test to check for blood, bacteria, ova, or parasites. Find out how this test is performed and when you can expect the results.
Stool Test: Fecal Blood Stool samples can provide information about a problem in the GI system. To test the stool for the presence of blood, a noninvasive test - the fecal occult blood test (FOBT) - is performed.
Yersiniosis Yersiniosis is an uncommon infection caused by the consumption of undercooked meat products, unpasteurized milk, or water contaminated by the bacteria.
Campylobacter Infections These bacterial infections can cause diarrhea, cramping, abdominal pain, and fever. Good hand-washing and food safety habits can prevent them.
Diarrhea Most kids battle diarrhea from time to time, so it's important to know what to do to relieve and even prevent it.
Shigella Infections Shigella are bacteria that can infect the digestive tract and cause a wide range of symptoms, from diarrhea, cramping, vomiting, and nausea, to more serious complications and illnesses.
iGrow iGrow
Sign up for our parent enewsletter