A laboratory test that investigates microbes, parasites, and signs of digestive disorders in a stool sample. It is used to identify the cause of diarrhea and abdominal complaints.
Indication
- Investigation of acute or chronic diarrhea
- Suspected bacterial enteritis (Salmonella, Shigella, Campylobacter)
- Suspected parasitic infection (Giardia, Entamoeba, helminths)
- Gastrointestinal complaints after travel abroad
- Investigation of food-borne poisoning
- Evaluation of malabsorption (fat, fiber analysis)
- Post-antibiotic diarrhea (suspected C. difficile)
Preparation
- Use of antibiotics and antiparasitic medications is reported to the physician 2-3 days in advance
- After radiologic studies with barium, a 1-week wait is required
- The stool container must be clean and dry
- Samples are not collected during menstruation
- Samples on 3 different days may be requested for parasite testing
How it's performed
- A stool sample is collected in the sterile container provided to the patient (it must not be mixed with urine)
- The sample is delivered to the laboratory within 1-2 hours
- Direct microscopic examination evaluates parasites, eggs, and cells
- For bacterial culture, the sample is plated on special media and incubated for 24-72 hours
- Antibiogram (antibiotic susceptibility) testing is performed on bacteria that grow
- If needed, C. difficile toxin testing and viral PCR analysis are added
Post-procedure
- Results are used in treatment planning
- If positive, appropriate antibiotic or antiparasitic treatment is started
- A control culture may be needed after treatment
- In recurrent cases, further investigations (colonoscopy, biopsy) are performed
Risks
- There is no procedural risk (the sample is collected by the patient)
- False-negative results (intermittent shedding of parasites)
- Results may be impaired in samples that are delivered late
- Antibiotic use may inhibit bacterial growth
FAQ
How long does it take to get results?
Microscopic examination is reported the same day, bacterial culture in 2-3 days, and parasite testing within 1-3 days.
Is one sample enough?
A single sample may be sufficient for bacterial culture. However, for parasite testing, samples on 3 different days are recommended because parasites are shed intermittently.
What kinds of microorganisms can be detected?
Bacteria such as Salmonella, Shigella, Campylobacter, and E. coli; parasites such as Giardia and Entamoeba; rotavirus; and C. difficile toxin can be detected.
Should I get tested if my diarrhea has resolved quickly?
Mild diarrhea may resolve on its own. However, testing is recommended in cases of fever, bloody diarrhea, prolonged complaints, or following travel.
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