Clostridioides difficile (C. Difficile)

CDI is toxin-mediated colitis that becomes possible when antibiotics disrupt the protective colonic microbiome. Spores can then persist and spread, while toxins A and B injure the mucosa; the same process that causes watery stool can progress to ileus, toxic megacolon, perforation, or sepsis. A diagnosis requires both compatible symptoms and laboratory evidence: at least 3 unformed stools in 24 hours plus a positive test for toxigenic C. difficile, such as a NAAT for toxin genes or an enzyme immunoassay for toxin B. A positive NAAT without diarrhea may indicate colonisation rather than infection. Bedside priorities are contact precautions, soap-and-water hand hygiene, review of recent antibiotics, hydration, and a focused search for worsening colitis or hemodynamic instability. Treatment choice then depends on whether this is an initial episode or recurrence and on the patient's response.