A-A+Home | Print | Email | Add This | Adjust text size

Back to tests and procedures

Salmonella Culture (Stool)

Does this test have other names?

Stool culture

What is this test?

This test looks for salmonella bacteria in your stool. Having these bacteria in your stool means you have a salmonella infection.

Salmonella infection takes many forms, but the most common in the U.S. is gastroenteritis, also called a "stomach bug." You can get it if you eat food contaminated by animal feces. Food is often contaminated during processing, such as when raw meat comes in contact with other foods. Undercooking meat, especially chicken, can also cause salmonella. Chicken eggs are a common carrier of salmonella.

Typhoid fever is another type of salmonella that may affect people who travel outside the U.S. Salmonella can also cause an invasive disease like osteomyelitis, or bone infection.

Why do I need this test?

You may need this test if your doctor suspects that you have a salmonella infection. Symptoms of salmonella may include:

  • Nausea

  • Headaches

  • Vomiting

  • Low-level fever

  • Abdominal pain

  • Diarrhea

If you have a salmonella infection, your diarrhea typically will have a strong odor. Sometimes you may also have blood in the stool.

The illness usually lasts for just a few days. Children younger than 3 months may have the infection for a longer period of time. In other children, the fever can last a few days, and diarrhea may last for about a week. Most cases of the disease go away without extensive treatment.

If you have been diagnosed with salmonella and work with children or people with a weakened immune system, or in the food industry, your employer may require multiple negative tests to prove that you no longer have salmonella.

What other tests might I have along with this test?

Your doctor may also order related stool cultures, such as an ova and parasites exam, or O&P, or a test for Clostridium difficile toxin.

You may also have a blood test if your doctor thinks it's possible that you have an advanced form of salmonella known as bacteremia. This infection of the blood affects about 5 percent of people who get salmonella.

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.

Normal test results are negative, meaning you don't have a salmonella infection. A positive result means you have a salmonella infection.

How is this test done?

This test requires a stool sample. Your doctor will tell you how to collect the sample and place it in a disposable specimen container with a lid. Don't collect fecal material from the toilet bowl or put toilet paper into the specimen container.

Does this test pose any risks?

This test poses no known risks.

What might affect my test results?

Other factors aren't likely to affect your test results.

How do I get ready for this test?

You don't need to prepare for this test. But be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.