Understanding the Gastrointestinal Profile (Stool PCR)

The Gastrointestinal Profile (Stool PCR) is a molecular diagnostic test that uses polymerase chain reaction (PCR) technology to identify genetic material from gastrointestinal pathogens in a stool sample. Unlike traditional stool cultures, PCR testing is faster, more sensitive, and able to detect multiple pathogens simultaneously.

This test is designed to identify the most common causes of infectious diarrhoea, gastroenteritis, abdominal pain, and persistent digestive symptoms, including bacteria, viruses, and parasites. It is particularly valuable when symptoms are severe, prolonged, recurrent, or when initial investigations have been inconclusive.

Because PCR detects pathogen DNA or RNA directly, it can identify infections even when organisms are present in low numbers or are difficult to culture.

The Gastrointestinal Profile (Stool PCR) includes detection of:

Viruses

• Adenovirus
• Astrovirus
• Norovirus GI/GII
• Rotavirus A
• Sapovirus (GI, GII, GIV, GV)

Bacteria

• Campylobacter species
• Clostridium difficile Toxin A/B
• Enteroaggregative Escherichia coli
• Enteropathogenic Escherichia coli
• Enterotoxigenic Escherichia coli (LT/ST)
• Enteroinvasive Escherichia coli / Shigella
• Shiga-like toxin producing Escherichia coli (Stx-1 / Stx-2)
• Shiga-like toxin producing Escherichia coli O157:H7
• Salmonella species
• Vibrio cholerae
• Vibrio parahaemolyticus
• Vibrio vulnificus
• Yersinia enterocolitica
• Plesiomonas shigelloides

Parasites

• Giardia lamblia
• Cryptosporidium species
• Cyclospora cayetanensis
• Entamoeba histolytica

When a Gastrointestinal Profile (Stool PCR) is recommended

This test is recommended when an infectious cause of gastrointestinal symptoms is suspected. Many gut infections cannot be reliably identified based on symptoms alone, making molecular testing essential for accurate diagnosis and treatment.

Testing may be appropriate if you:

• Have persistent or severe diarrhoea
• Experience abdominal pain, cramping, or bloating
• Have nausea or vomiting lasting more than a few days
• Have fever associated with digestive symptoms
• Have recently travelled abroad
• Have consumed potentially contaminated food or water
• Have symptoms following antibiotic use
• Have recurrent or unexplained gastrointestinal symptoms

Benefits of the Gastrointestinal Profile (Stool PCR)

• Broad pathogen coverage in one test
  Detects bacterial, viral, and parasitic causes simultaneously.
• High sensitivity and specificity
  PCR identifies pathogens missed by culture methods.
• Faster results than traditional stool cultures
  Enables quicker diagnosis and treatment decisions.
• Identifies toxin-producing organisms
  Includes detection of C. difficile toxins and Shiga toxins.
• Useful for acute and chronic symptoms
  Suitable for both short-term illness and persistent issues.
• Guides targeted treatment
  Helps avoid unnecessary antibiotics.
• Non-invasive sample collection
  Uses a stool sample only.
• Reduces diagnostic uncertainty
  Provides clear identification of infectious causes.

How the test is carried out

This test is performed using a stool sample, collected at home.

Stool sample collection

• A stool collection kit is provided
• You collect the sample at home following clear instructions
• The sample is returned to the laboratory promptly
• PCR analysis is performed to detect pathogens

Clinic attendance is not required for sample collection.

Understanding your Gastrointestinal Profile (Stool PCR) results

No pathogens detected

No bacterial, viral, or parasitic DNA identified.

Typical interpretation:

• Infectious cause unlikely

Symptoms may be due to non-infectious conditions such as IBS or food intolerance.

Single pathogen detected

One infectious organism identified.

Typical interpretation:

• Likely cause of symptoms

Targeted treatment or supportive care may be recommended.

Multiple pathogens detected

More than one organism identified.

Typical interpretation:

• Mixed gastrointestinal infection

Clinical correlation is important to determine relevance and management.