Escherichia coli (E. coli) quantitative culture from stool sample

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms like diarrhea, abdominal pain, fever, or other signs of a bacterial infection. It’s also used to confirm infections in people with recurring gastrointestinal problems or those with weakened immune systems. Sometimes, it’s done as part of routine testing for certain conditions or after exposure to known sources of infection.

What to Expect Before the Test

No special preparation is needed for this test. You may be asked to collect a stool sample in a clean container at home or provided at your healthcare facility. Follow your provider’s instructions carefully to ensure the sample is representative. Avoid using toilet paper or cleaning agents in the sample.

What Happens During the Test

The collected stool sample is sent to a lab, where it is mixed with a special growth medium to encourage bacterial growth. Over several days, the lab will culture the sample to identify and count E. coli and other bacteria. Results may take 2–5 days or longer, depending on the lab’s processes.

What the Results Mean

If E. coli is detected, it means the bacteria are present in your stool. The count (if provided) helps determine the severity of the infection. A positive result may indicate a bacterial infection, but it doesn’t always mean it’s causing symptoms. Your healthcare provider will discuss the results with you and may recommend further testing or treatment based on your symptoms and lab findings.