Escherichia coli (E. coli) stool culture with antimicrobial susceptibility testing (AST)

What Is This Test For?

A stool sample is examined to detect *E. coli*, a common type of bacteria found in the intestines. If present, the test also assesses whether the bacteria are resistant to certain antibiotics, helping your healthcare provider choose the most effective treatment.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms like diarrhea (especially with blood or mucus), abdominal pain, fever, or if you’ve recently traveled to areas with different hygiene standards. It can also be used to confirm infections in people with recurring urinary tract infections or other health concerns linked to bacterial contamination.

What to Expect During the Test

You’ll provide a fresh stool sample (usually collected in a special container) to a lab. The sample is then grown in a controlled environment to identify *E. coli* and, if present, how it responds to antibiotics. Results typically take 2–5 days, depending on the lab’s process.

Preparation and Sample Collection

No special preparation is needed, but avoid using laxatives or enemas 24 hours before testing. Collect the sample early in the morning for best accuracy. If you’re using a collection kit, follow the instructions carefully to prevent contamination.