Skip to content

Complete Blood Count (CBC): What You Need to Know About This Common Blood Test

Published: August 9, 2026Updated: August 17, 2026

A laboratory test that identifies harmful bacteria in your stool sample to diagnose gastrointestinal infections.

Quick summary

{"This test detects disease-causing bacteria in your digestive tract","A stool sample is collected and sent to a laboratory for analysis","Results help your doctor determine if you need antibiotic treatment"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
17968-9
Short code
STBC6
Synonyms
Bacteria Stl Cult org #6
Category
chemistry
Sample
stool
Container
Sterile, wide-mouth, leak-proof plastic container with screw-cap lid; or Cary-Blair transport medium for delayed transport
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
culture
CPT
87045
SNOMED
407675009
Specimen volume
5-10 grams (approximately 1-2 teaspoons) of fresh stool, or equivalent swab of stool
Stability
Unpreserved stool: process within 2 hours of collection at room temperature; refrigerated (2-8°C): up to 24 hours; in Cary-Blair transport medium: up to 72 hours at room temperature or refrigerated
TAT
48–96 hours
Order
routine

What is a complete blood count (CBC) and why might my doctor order it for me?

The Bacteria # 6 identified in Stool by Culture test is a laboratory procedure that grows and identifies specific disease-causing bacteria from a stool sample. The test looks for harmful bacteria that may be causing symptoms such as diarrhea, stomach pain, or fever. When bacteria are found, the laboratory can also test which antibiotics will work best to treat the infection.

How is the blood sample collected, and do I need to prepare before the test?

You will be given a clean, sterile container for collecting your stool sample. It is important to collect a fresh sample and avoid mixing it with urine or water from the toilet. Follow the instructions provided by your healthcare provider or laboratory carefully. The sample should be delivered to the laboratory as soon as possible, preferably within a few hours of collection.

What happens to my blood sample after it arrives at the laboratory for analysis?

In the laboratory, technicians place small amounts of your stool sample onto special growth materials (culture media) that help bacteria multiply. After allowing time for bacteria to grow, experts examine the colonies under a microscope and perform additional tests to identify the exact type of bacteria present. This process typically takes 2-5 days.

What do my complete blood count results mean, and when should I discuss them with my doctor?

A positive result means that disease-causing bacteria were found in your stool, which likely explains your symptoms. Your doctor will discuss the specific bacteria identified and recommend appropriate treatment. A negative result means no harmful bacteria were found, but this does not rule out other causes of your symptoms such as viruses, parasites, or non-infectious conditions.

Reference range

Adult: 10-40 U/LN/A

Specimen: stool

No special dietary restrictions or fasting required. Patient should avoid taking antacids, bismuth subsalicylate, or anti-diarrheal medications prior to specimen collection if possible. Antibiotic usage should be noted on the requisition.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings2

Frequently asked questions

Do I need to prepare anything before the test?
Generally, no special preparation is needed. However, avoid taking antibiotics, antacids, or anti-diarrhea medications before collecting your sample unless directed by your doctor, as these may affect test results. Stay hydrated and follow your doctor's specific instructions.
Is the test painful?
No. Collecting a stool sample is painless. You do not need to give blood or undergo any invasive procedure. The process only requires collecting a small amount of stool in the provided container.
How long does it take to get results?
Results typically take 2-5 days because bacteria need time to grow in the laboratory. Some bacteria may require additional time for identification or antibiotic sensitivity testing.
What happens if bacteria are found?
If disease-causing bacteria are identified, your healthcare provider will determine if treatment is needed. Many bacterial infections resolve on their own without antibiotics. However, for severe cases or certain types of bacteria, your doctor may prescribe antibiotics to help you recover faster.
Can I eat normally before the test?
Yes, you can eat and drink normally before providing a stool sample unless your doctor gives you specific dietary instructions. There are no food restrictions for this test.
  1. 1
    Stool Culture Test - MedlinePlusSource
  2. 2
    Bacterial gastroenteritis - Mayo ClinicSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy