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Clostridioides difficile infection — RCPSC IM MCQ

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HardInfectious DiseasesClostridioides difficile infectionRCPSC IM

A 67-year-old man develops watery diarrhea 6 times daily after 5 days of ceftriaxone for pyelonephritis. He has leukocytes 18 x 10^9/L and creatinine 160 umol/L from a baseline of 90. He has no ileus or megacolon. Stool laxative use has been excluded. What is the most appropriate investigation?

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Correct answer: B — Stool C difficile toxin assay with nucleic acid amplification testing algorithm

New significant diarrhea after antibiotic exposure with leukocytosis and kidney injury warrants testing for C difficile using a local two-step toxin and molecular algorithm. Colonoscopy is not first-line for typical cases.

Reference: Association of Medical Microbiology and Infectious Disease Canada; IDSA/SHEA CDI guidance