What is the character of diarrhea in Clostridium difficile (C. diff) infection?

Characteristics of Diarrhea in Clostridioides difficile Infection

Diarrhea in Clostridioides difficile infection typically presents as profuse watery stools that are usually non-bloody, occurring at least three times in 24 hours, and is often accompanied by abdominal pain and cramps. 1

Primary Characteristics of C. difficile Diarrhea

• Watery, non-bloody diarrhea is the hallmark symptom, defined as three or more unformed stools within 24 hours 1
• Diarrhea may be absent initially in some patients, particularly surgical patients with ileus, making diagnosis challenging 1
• Hyperactive bowel sounds are commonly present due to increased intestinal motility and inflammation 2
• Abdominal pain and cramping typically accompany the diarrhea, ranging from mild to severe 1
• Prolonged diarrhea can lead to electrolyte imbalances and dehydration 1

Severity-Based Characteristics

Mild-Moderate CDI

• Diarrhea with mild abdominal pain and cramps 1
• May result in altered electrolyte balance and dehydration if prolonged 1
• Can significantly increase morbidity in patients with severe comorbidities, particularly after surgery 1

Severe CDI

• Increased abdominal cramping and pain 1
• Systemic features including fever (>38.5°C), leukocytosis (WBC >15 × 10^9/L), and hypoalbuminemia (albumin <2.5 g/dL) 1
• The absence of diarrhea may paradoxically signal progression to fulminant infection 1
• Severe abdominal pain with bloody stools may occasionally be present 1

Fulminant CDI

• May present with shock, ileus, or toxic megacolon rather than diarrhea 3
• Bowel sounds typically diminish or become absent if ileus or toxic megacolon develops 2
• Can progress to colonic perforation, peritonitis, and septic shock 1

Special Considerations

• In patients with inflammatory bowel disease (IBD), the clinical presentation of C. difficile may overlap with an IBD flare 1, 2
• C. difficile should be suspected in any resident of long-term care facilities exposed to systemic antimicrobial therapy in the previous 30 days who experiences at least three watery or unformed stools in 24 hours and/or abdominal pain 1
• Immunocompromised patients may have atypical presentations with less pronounced bowel sound changes 2
• The absence of pseudomembranes in C. difficile-associated diarrhea is more common in patients using immunosuppressive agents 1

Pathophysiological Basis

• C. difficile toxins A and B cause colonocyte death and colonic inflammation 2
• These toxins promote activation of Rho GTPases leading to disorganization of the cytoskeleton of colonocytes 2
• Human serum albumin can bind C. difficile toxins A and B, impairing their internalization into host cells, which may explain the increased CDI severity in hypoalbuminemic patients 1

Diagnostic Implications

• Hyperactive bowel sounds in a patient with recent antibiotic use should raise suspicion for CDI 2
• Testing should only be performed on symptomatic patients with clinically significant diarrhea to avoid detecting asymptomatic colonization 4
• A single cup specimen of diarrheal stool should be submitted for C. difficile cytotoxin assay; if the first test is negative and fever or abdominal pain and diarrhea persist despite discontinuing antibiotics, 1 or 2 additional diarrheal stool specimens should be submitted for toxin assay 1