Colitis Secondary to Clostridioides difficile Infection
Yes, colitis can definitely be secondary to Clostridioides difficile (C. diff) infection, and this is one of the most common and clinically significant forms of infectious colitis. 1
Pathophysiology and Clinical Presentation
- C. difficile colitis occurs when the normal gut microbiota is disrupted (typically by antibiotics), allowing C. difficile to proliferate and produce toxins that damage the colonic mucosa 1, 2
- The resulting inflammation can range from mild diarrhea to severe pseudomembranous colitis with potentially life-threatening complications 3
- C. difficile infection (CDI) produces a spectrum of disease severity:
- Mild to moderate diarrhea without colitis
- Colitis without pseudomembrane formation
- Pseudomembranous colitis (characterized by yellow-white plaques on the colonic mucosa)
- Fulminant colitis with potential complications including toxic megacolon 1
Diagnostic Features of C. difficile Colitis
Clinical Features
- Diarrhea (>3 unformed bowel movements in 24 hours) is the hallmark symptom 4
- Additional symptoms may include:
- Abdominal pain and cramping
- Fever (core body temperature >38.5°C)
- Rigors (uncontrollable shaking)
- Signs of severe systemic inflammatory response 1
Laboratory Findings
- Presence of C. difficile toxin A or B in stool samples 4
- Marked leukocytosis (leukocyte count >15 × 10⁹/L)
- Elevated serum creatinine (>50% above baseline)
- Elevated serum lactate in severe cases 1
Endoscopic Findings
- Pseudomembranes (pathognomonic when present)
- Edema, erythema, friability, and ulceration of colonic mucosa
- Flexible sigmoidoscopy may be helpful in diagnosis when there is high clinical suspicion but negative stool tests 1
Imaging Findings
- CT scan may show:
- Colonic wall thickening
- "Accordion sign" (alternating areas of high and low attenuation in the colonic wall)
- "Double-halo" or "target sign"
- Pericolonic fat stranding
- Ascites 1
Differentiating from Other Forms of Colitis
- C. difficile colitis must be distinguished from other forms of colitis, including inflammatory bowel disease (IBD) 1
- C. difficile can also complicate existing IBD, making diagnosis challenging 1
- Key differences from IBD:
- History of antibiotic exposure (though not always present)
- Absence of chronic changes on histology
- Presence of pseudomembranes (though these may be absent in patients on immunosuppressive therapy) 1
Treatment Approach
Non-Severe C. difficile Colitis
- Discontinue the inciting antibiotic if possible 1
- For mild disease clearly induced by antibiotics, stopping the antibiotic may be sufficient with close monitoring 1
- For non-severe initial episodes: oral metronidazole 500 mg three times daily for 10 days 1
Severe C. difficile Colitis
- Oral vancomycin 125 mg four times daily for 10 days 1
- If oral therapy is not possible:
- Intravenous metronidazole 500 mg three times daily for 10 days
- Plus intracolonic vancomycin 500 mg in 100 mL normal saline every 4-12 hours 1
Fulminant C. difficile Colitis
- Surgical consultation for potential colectomy in cases of:
- Colonic perforation
- Systemic inflammation not responding to antibiotics
- Toxic megacolon
- Severe ileus 1
Recurrent C. difficile Colitis
- For first recurrence, treatment is similar to initial episode based on severity 1
- For second or subsequent recurrences:
Important Clinical Pitfalls
- Avoid antiperistaltic agents and opiates as they can mask symptoms and potentially worsen disease 1
- Recognize that C. difficile infection can occur with virtually any antibiotic, not just those commonly associated with it 5, 6
- In patients with IBD, absence of pseudomembranes does not rule out C. difficile infection 1
- Serum lactate >5.0 mmol/L indicates severe disease and may guide timing of surgical intervention 1
- Continued use of antibiotics for other infections during C. difficile treatment significantly increases risk of recurrence 1