Key facts
- Four families: bacteria, viruses, parasites and fungal overgrowth.
- Diagnosis differs by pathogen: no single test finds everything.
- Acute vs comprehensive: severe illness needs a provider now; comprehensive testing shines for the full picture and recovery.
- Recovery matters: infections leave the microbiome disrupted — that’s where retesting helps.
“Gut infection” covers a lot of ground — a bacterium picked up from food, a virus that sweeps through a household, a parasite from contaminated water, or an overgrowth of an organism that’s normally kept in check. They can look similar from the outside (diarrhea, cramping, nausea) but are found, treated and recovered from very differently. These guides explain each honestly, including where a comprehensive stool test does — and does not — belong.
The main types
C. difficile
Antibiotic-associated diarrhea driven by toxins A and B — and why testing distinguishes infection from carriage.
Read more →Candida & gut yeast
What’s real, what’s wellness myth, and why a positive stool Candida isn’t a diagnosis.
Read more →Salmonella (backyard poultry)
The recurring seasonal outbreak, who’s at risk, and recovering afterward.
Read more →Norovirus & recovery
The “stomach bug,” and why some guts stay off for weeks afterward.
Read more →How gut infections are tested
Different infections need different tests, and routine panels only look for what they’re asked to find. Comprehensive molecular testing takes a different approach — screening for many organisms at once by qPCR. Explore what a comprehensive panel covers:
Acute vs comprehensive testing
Use this educational tool to think through whether comprehensive testing fits your situation:
Recovery is part of the story
Whatever the cause, an infection can leave behind inflammation and a disrupted microbiome, and post-infectious gut symptoms are common. Practitioners use a follow-up GI-MAP to confirm clearance and check gut-health markers — the measure-adjust-remeasure workflow. Parasites are covered in depth in our parasites & testing guide and the Cyclospora guide.
The GI-MAP™ screens 85+ markers — bacteria, viruses, parasites, fungi and gut-health markers — from one at-home sample.
Order Your GI-MAP™ Test → How it worksFrequently asked questions
What is a gut infection?
Illness caused by a bacterium, virus, parasite or fungal overgrowth in the digestive tract, usually with diarrhea, cramping, nausea or fatigue.
How are gut infections diagnosed?
By stool testing (and sometimes blood tests or endoscopy). Routine tests look for specific pathogens; comprehensive panels like the GI-MAP screen for many at once. Severe illness needs a provider.
Can GI-MAP detect gut infections?
It detects many bacterial, viral, parasitic and fungal targets by qPCR — best for a comprehensive picture and recovery, not as an emergency test.
Sources & further reading
- CDC — C. difficile infection.
- CDC — Salmonella outbreaks linked to backyard poultry (2026).
- CDC — About Norovirus.
- Mayo Clinic — Candida cleanse: what the evidence shows.
- Diagnostic Solutions Laboratory — GI-MAP test overview & methodology.