Management of Adult Diarrhea with Uncertain C. difficile Status

Diagnostic Approach

The American Gastroenterological Association recommends testing for C. difficile immediately in any adult with diarrhea (≥3 unformed stools in 24 hours) who has received antibiotics, is hospitalized, or has healthcare exposure, but do not delay empiric treatment if the clinical picture suggests severe disease 1, 2
The Infectious Diseases Society of America recommends testing only symptomatic patients with diarrhea (≥3 unformed stools in 24 hours) who have risk factors including recent antibiotic use, healthcare exposure, older age, or immunosuppression 1, 3
The Society for Healthcare Epidemiology of America recommends never testing asymptomatic patients or performing "test of cure" after treatment, as up to 56% of treated patients shed C. difficile asymptomatically for up to 6 weeks 1

The American College of Gastroenterology recommends using multistep algorithms combining PCR for toxin genes with toxin enzyme immunoassay (sensitivity 0.68-1.00, specificity 0.92-1.00) or single-step PCR on liquid stool for best diagnostic performance 3
The European Society of Clinical Microbiology and Infectious Diseases recommends that a positive nucleic acid amplification test (NAAT) alone in the appropriate clinical context is reasonable for diagnosis 2

The American College of Emergency Physicians recommends obtaining complete blood count, metabolic panel, C-reactive protein, and blood cultures if fever is present to assess for severe disease 4
The Infectious Diseases Society of America recommends monitoring for signs of severe/fulminant C. difficile infection, including leukocytosis ≥15 × 10⁹ cells/L or leukocytosis with left shift 5, 4

The American Gastroenterological Association recommends starting empiric treatment immediately if there is strong clinical suspicion (recent antibiotics + diarrhea + leukocytosis) 4
The Society for Healthcare Epidemiology of America recommends starting empiric treatment immediately if severe disease indicators are present (see above) 5, 6

The American College of Gastroenterology recommends using oral vancomycin 125 mg four times daily for mild-to-moderate suspected C. difficile 1
The European Society of Clinical Microbiology and Infectious Diseases recommends using metronidazole for mild disease when vancomycin is unavailable 1

The American College of Emergency Physicians recommends discontinuing the causative antibiotic immediately if clinically feasible 6
The Infectious Diseases Society of America recommends avoiding antiperistaltic agents (loperamide, diphenoxylate) in suspected C. difficile as they may precipitate toxic megacolon 8

The American Gastroenterological Association recommends monitoring for treatment failure, and if no improvement within 48-72 hours or clinical deterioration occurs, obtaining CT imaging to assess for complications (toxic megacolon, perforation, severe colitis) 4, 6
The Society for Healthcare Epidemiology of America recommends escalating to fulminant disease protocol if indicated 6
The American College of Surgeons recommends obtaining urgent surgical consultation if peritonitis, perforation, or megacolon develops 4, 6