How do you treat a patient colonized with Clostridioides difficile (C. diff) who is experiencing diarrhea?

Treatment of C. difficile Colonization with Diarrhea

For a patient colonized with C. difficile who is experiencing diarrhea, oral vancomycin 125 mg four times daily for 10 days is the recommended treatment, as this represents active C. difficile infection (CDI) rather than mere colonization. 1, 2

Diagnosis Considerations

• Diarrhea in a patient colonized with toxigenic C. difficile should be considered active C. difficile infection (CDI) requiring treatment, not just colonization 1
• Microbiological evidence of toxin-producing C. difficile in stools with diarrhea without another cause confirms the diagnosis of CDI 1
• Asymptomatic colonization transitions to active infection when patients develop diarrhea, which is defined as loose stools taking the shape of the container 1

Treatment Algorithm

First-line Treatment:

• For non-severe CDI (stool frequency <4 times daily; no signs of severe colitis):
  • Oral vancomycin 125 mg four times daily for 10 days 1, 2
  • Metronidazole is no longer recommended as first-line therapy according to more recent guidelines 3

For Severe CDI (any of these signs):

• Marked leukocytosis (>15 × 10^9/L)
• Serum creatinine rise (>50% above baseline)
• Hemodynamic instability or signs of septic shock
• Signs of peritonitis or ileus 1

Treatment:

• Oral vancomycin 125 mg four times daily for 10 days 1
• If oral therapy is impossible: intravenous metronidazole 500 mg three times daily plus intracolonic vancomycin 500 mg in 100 mL normal saline every 4-12 hours 1

Important Considerations

• Antiperistaltic agents and opiates should be avoided as they can worsen the condition 1
• Stop any inducing antibiotics if possible, as they disrupt the intestinal microflora 1, 4
• Place patient on contact (enteric) precautions in a private room with en-suite facilities to prevent transmission 1
• Hand hygiene with soap and water (not alcohol-based sanitizers) is essential as alcohol does not kill C. difficile spores 1

Monitoring Response

• Treatment response is indicated by decreased stool frequency or improved stool consistency after 3 days 1
• Treatment failure is defined as absence of response 1
• Monitor renal function during and after treatment, especially in patients >65 years, as vancomycin can cause nephrotoxicity 2

Recurrence Management

• For first recurrence: same treatment as initial episode 1
• For second or subsequent recurrences: vancomycin 125 mg four times daily for at least 10 days, followed by a tapered and/or pulsed regimen 1
• Consider bezlotoxumab (monoclonal antibody against C. difficile toxin B) as adjunctive therapy for patients with multiple risk factors for recurrence 3
• Fecal microbiota transplantation should be considered for multiple recurrences 5, 3

Important Pitfalls to Avoid

• Do not treat asymptomatic C. difficile colonization without diarrhea, as this is not indicated and may worsen antibiotic resistance 1, 6
• Do not rely on alcohol-based hand sanitizers for hand hygiene when caring for C. difficile patients 1
• Do not use fluoroquinolones if possible, as they are associated with increased risk of CDI, particularly with the NAP1/027 strain 7, 4
• Do not discontinue contact precautions until diarrhea has resolved for at least 48 hours 1
• Do not assume colonization is protective; colonized patients have a 5.9 times higher risk of developing CDI compared to non-colonized patients 8