Colitis Secondary to Clostridioides difficile Infection

Pathophysiology and Clinical Presentation

C. difficile colitis occurs when the normal gut microbiota is disrupted, allowing C. difficile to proliferate and produce toxins that damage the colonic mucosa, resulting in a spectrum of disease severity, including mild to moderate diarrhea, colitis, pseudomembranous colitis, and fulminant colitis 1, 2
The disease severity can range from mild diarrhea to severe pseudomembranous colitis with potentially life-threatening complications, including colitis without pseudomembrane formation, pseudomembranous colitis, and fulminant colitis 1, 2

Additional symptoms of C. difficile colitis may include abdominal pain and cramping, fever, rigors, and signs of severe systemic inflammatory response 1, 3
Laboratory findings may include marked leukocytosis, elevated serum creatinine, and elevated serum lactate in severe cases 1
Endoscopic findings may include edema, erythema, friability, and ulceration of colonic mucosa, and flexible sigmoidoscopy may be helpful in diagnosis when there is high clinical suspicion but negative stool tests 3, 4

CT scan may show colonic wall thickening, "accordion sign", "double-halo" or "target sign", pericolonic fat stranding, and ascites 1, 4, 5

C. difficile colitis must be distinguished from other forms of colitis, including inflammatory bowel disease (IBD), and key differences from IBD include history of antibiotic exposure, absence of chronic changes on histology, and presence of pseudomembranes 3, 6

For non-severe initial episodes, oral metronidazole 500 mg three times daily for 10 days may be sufficient, while for severe C. difficile colitis, oral vancomycin 125 mg four times daily for 10 days is recommended 1
For fulminant C. difficile colitis, surgical consultation for potential colectomy may be necessary in cases of colonic perforation, systemic inflammation not responding to antibiotics, toxic megacolon, or severe ileus 1, 4

For first recurrence, treatment is similar to initial episode based on severity, while for second or subsequent recurrences, vancomycin 125 mg four times daily for at least 10 days or a tapered and/or pulsed vancomycin regimen may be considered 1

Avoid antiperistaltic agents and opiates as they can mask symptoms and potentially worsen disease, and recognize that C. difficile infection can occur with virtually any antibiotic 1
In patients with IBD, absence of pseudomembranes does not rule out C. difficile infection, and serum lactate >5.0 mmol/L indicates severe disease and may guide timing of surgical intervention 1, 3
Continued use of antibiotics for other infections during C. difficile treatment significantly increases risk of recurrence 4