General Principles: Frequently seen after systemic antimicrobial therapy .
Diagnosis: Clinical Presentation – Symptoms may range from mild or moderate watery diarrhea to severe and potentially fatal pseudomembranous colitis. Abdominal pain, cramping, low-grade fever, and leukocytosis are often present. Fulminant diseases can manifest as colonic ileus or toxic megacolon leading to bowel perforation.
Differential Diagnosis: Antibiotic-associated osmotic diarrhea without Clostridium difficile infection should be considered and will resolve after withdrawal of the antibiotic.
Diagnostic Testing: Testing for C. difficile infection is recommended in patients with unexplained and new-onset ≥3 unformed stools in 24 hours. Diagnosis is made by detection of toxigenic C. difficile in diarrheal stool through nucleic acid amplification test (NAAT) or enzyme immunoassay . Visualization of pseudomembranes on colonoscopy or sigmoidoscopy with biopsy can also be diagnostic for C. difficile infection.
- For an initial episode of C. difficile infection (severe or nonsevere), treatment should consist of vancomycin for 10 days or fidaxomicin for 10 days and discontinuation of the offending antibiotic if possible.
- For fulminant infections complicated by ileus, toxic megacolon, hypotension, or shock, surgery consultation should be obtained along with treatment consisting of vancomycin or by nasogastric tube in combination with metronidazole. If ileus is present, consider adding rectal instillation of vancomycin. In some cases, colectomy may be necessary.
- Endpoint of therapy is cessation of diarrhea; do not retest stool for toxin clearance. Avoid antimotility agents in severe disease.
- Recurrence is common and is treated with vancomycin using tapered and pulsed regimens. Adjunctive therapy with oral rifaximin is sometimes used.
- Fecal microbiota transplantation may be considered for patients with multiple recurrences despite appropriate antibiotic treatment