Clostridioides difficile Infection

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GI NOTES

Clostridioides difficile Infection

Key points

Test only patients with 3 or more unformed stools in 24 hours who are not taking laxatives. Do not test formed stool or test for cure.
Use a two-step approach (for example GDH plus toxin, or PCR plus toxin) to separate infection from colonization.
First episode: fidaxomicin 200 mg twice daily or oral vancomycin 125 mg four times daily, each for 10 days. Metronidazole is only for non-severe cases when neither is available.
Fulminant disease (shock, ileus, megacolon): high-dose vancomycin by mouth and rectum, IV metronidazole, and an early surgical consult.
Recurrence is common. After two or more recurrences, use fecal microbiota transplant or an FDA-approved microbiome product.

1. Risk factors and diagnosis

Risk factors: recent antibiotics (especially clindamycin, fluoroquinolones, cephalosporins, broad-spectrum penicillins), age over 65, hospitalization or long-term care, IBD, immunosuppression, possibly acid suppression.
Testing: 3 or more unformed stools in 24 hours, no laxatives in the past 48 hours. A positive PCR alone may reflect colonization; a positive toxin supports true infection.
Do not test asymptomatic patients or repeat testing within 7 days, and do not test for cure.

2. Severity and treatment

Severity	Definition	Treatment
Non-severe	WBC 15,000/mm3 or less and creatinine below 1.5 mg/dL	Fidaxomicin 200 mg twice daily for 10 days (preferred) or vancomycin 125 mg orally four times daily for 10 days
Severe	WBC above 15,000/mm3 or creatinine 1.5 mg/dL or higher	Same drugs and doses as non-severe
Fulminant	Hypotension or shock, ileus, or megacolon	Vancomycin 500 mg four times daily by mouth or NG tube, plus rectal vancomycin if ileus, plus IV metronidazole 500 mg every 8 hours; urgent surgical consult

Stop the inciting antibiotic if possible; if antibiotics must continue, keep treating C. difficile until they are finished.
Avoid antiperistaltic drugs in active infection.
Surgery in fulminant disease: rising lactate, WBC above about 25,000, worsening shock or organ failure, perforation or toxic megacolon. Options are subtotal colectomy or diverting loop ileostomy with colonic lavage.

3. Recurrence

FIGURE: MANAGING C. DIFFICILE OVER TIME

First episode: fidaxomicin or vancomycin, 10 days

First recurrence: fidaxomicin (standard or extended-pulsed) or vancomycin taper and pulse

Second or later recurrence: antibiotic course, then fecal microbiota transplant or an approved microbiome product

Original diagram based on the ACG 2021 and IDSA/SHEA 2021 guidelines.

Recurrence occurs in about 1 in 5 patients after a first episode and more after each recurrence.
Microbiome therapies (given after finishing antibiotics): conventional fecal microbiota transplant (usually by colonoscopy), fecal microbiota live-jslm (rectal), and fecal microbiota spores live-brpk (oral capsules).
Bezlotoxumab, previously used to prevent recurrence, has been discontinued in the US.
Fecal transplant can be considered for fulminant disease not responding to antibiotics when surgery is not an option.

4. Prevention

Antibiotic stewardship is the most effective measure.
Contact precautions with gloves and gowns; wash hands with soap and water, because alcohol gels do not kill spores. Clean rooms with sporicidal agents.
Review the need for acid suppression.
Probiotics are not recommended for primary prevention by IDSA; evidence is limited.

5. High-yield pearls

Oral vancomycin is not absorbed, so IV vancomycin does not treat C. difficile.
Ileus can cause severe disease with little or no diarrhea; think of it in a sick patient with a distended abdomen.
Always test for C. difficile in an IBD flare.
Leukocytosis without another cause in a hospitalized patient on antibiotics should raise suspicion.

Self-check questions

A patient on daily lactulose has 4 loose stools. Should you send C. difficile testing?
WBC 18,000 and creatinine 1.7 mg/dL with positive toxin. Severity and treatment?
Hypotension and ileus with C. difficile. Treatment?
Third episode of C. difficile. What prevents further recurrence best?

Answers: (1) Usually not; laxatives explain the diarrhea, so stop them and reassess. (2) Severe; fidaxomicin or oral vancomycin for 10 days. (3) Fulminant: oral and rectal vancomycin, IV metronidazole, ICU care, and surgical consultation. (4) Fecal microbiota transplant or an approved microbiome product after antibiotics.

References

Kelly CR, Fischer M, Allegretti JR, et al. ACG Clinical Guidelines: Prevention, Diagnosis, and Treatment of Clostridioides difficile Infections. Am J Gastroenterol. 2021;116(6):1124-1147.
Johnson S, Lavergne V, Skinner AM, et al. Clinical Practice Guideline by the IDSA and SHEA: 2021 Focused Update Guidelines on Management of Clostridioides difficile Infection in Adults. Clin Infect Dis. 2021;73(5):e1029-e1044.
McDonald LC, Gerding DN, Johnson S, et al. Clinical Practice Guidelines for Clostridium difficile Infection in Adults and Children: 2017 Update by IDSA and SHEA. Clin Infect Dis. 2018;66(7):e1-e48.

For educational purposes only. This note does not replace clinical judgment or local protocols. Check doses against current labeling and institutional guidance.