Mar 6, 2024 · There are four laboratory tests used to diagnose Clostridioides difficile infection or CDI.

C. diff testing checks a sample of your stool (poop) for signs of an infection with a bacteria called C. diff. C. diff is also called C. difficile or Clostridioides difficile.

Table 1. Summary of performance characteristics of various test methods for C. difficile detection .

Rarely, to help confirm a diagnosis of C. difficile infection, a health care provider might check the inside of the colon. Tests used are either flexible sigmoidoscopy or colonoscopy.

Clostridioides difficile, or C. diff, is a highly contagious bacterium that causes diarrhea and colitis. It often infects people who’ve recently taken antibiotics.

Toxigenic culture (TC), formerly the gold standard test, involves the culturing of C. difficile from stool; cytotoxic assays are then used to test isolates for cytotoxin production.

You can also click here to read the full guide on C. diff testing. It explains each test in plain English, shows how to interpret different result combos, and helps you make sense of your own test report.

Sep 30, 2025 · The test is done to see if diarrhea that won't go away was caused by Clostridioides difficile (C. diff) toxins.

Mar 5, 2024 · Order a C. diff test if other etiologies of diarrhea such as stool softener or laxative were not used. Wear gloves and a gown when treating patients with potential infectious diarrhea, including C. …

The currently available tests for CDI, particularly the molecular tests (C diff PCR and GI Panel) are highly sensitive and may detect levels of the bacteria which are not clinically meaningful.