Clostridioides difficile Infection (CDI) Treatment — free guideline decision tool

This tool gives the Clostridioides difficile infection regimen by episode and severity, covering initial, recurrent, and fulminant disease.

Initial (non-severe/severe) → fidaxomicin or oral vancomycin × 10 days. First recurrence → fidaxomicin or vancomycin taper-pulse. Multiple recurrences → taper-pulse/rifaximin/FMT. Fulminant → high-dose vancomycin + IV metronidazole + surgery.

Use to choose fidaxomicin or vancomycin for initial/recurrent CDI, taper-pulse or FMT for multiple recurrences, and high-dose vancomycin + IV metronidazole for fulminant disease.

Metronidazole is no longer a first-line agent and is reserved for non-severe disease only when a preferred drug is unavailable. (original synthesis · not guideline verbatim) A test of cure is not performed, since asymptomatic carriage can persist. Bezlotoxumab may be added to reduce recurrence in high-risk patients.

For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.

Inputs: Episode Initial, Severity Non-severe (WBC ≤ 15,000 and creatinine ≤ 1.5 mg/dL) → Result: Regimen Fidaxomicin or vancomycin (oral)（Treatment: Initial (non-severe or severe): fidaxomicin 200 mg bid × 10 days (preferred, fewer recurrences) or vancomycin 125 mg qid × 10 days PO; both superior to metronidazole, Severity: Non-severe (WBC ≤ 15,000 and creatinine ≤ 1.5 mg/dL), General: Stop inciting antibiotics where possible, avoid antimotility agents; metronidazole only if a first-line drug is unavailable and disease is non-severe; do not perform a test of cure） Inputs: Episode Multiple recurrences, Severity Fulminant (+ hypotension/shock/ileus/toxic megacolon) → Result: Regimen Fulminant: high-dose vancomycin + IV metronidazole（Fulminant treatment: Vancomycin 500 mg qid PO/NG + IV metronidazole (add vancomycin retention enema if ileus is present); fidaxomicin not studied in fulminant disease, Surgery: Toxic megacolon/perforation/shock or no improvement after 48–72 h of drug therapy: surgical consult for subtotal colectomy; fecal microbiota transplant (FMT) may be considered if refractory, Support: Fluid resuscitation, correct electrolytes, avoid antimotility agents; stop the inciting antibiotics and proton-pump inhibitors where possible）