Clostridioides difficile (C. Difficile)

Clostridioides difficile is an anaerobic, spore-forming, gram-positive bacillus. Antibiotics can reduce the normal intestinal flora that ordinarily suppresses its growth, allowing toxigenic C. difficile to proliferate. Its spores persist on surfaces and resist routine cleaning, which helps explain transmission in healthcare settings. Toxin A, an enterotoxin, promotes intestinal fluid secretion. Toxin B, a cytotoxin, injures colonic epithelial cells. The resulting inflammation causes watery diarrhea, abdominal cramping, fluid loss, and sometimes pseudomembranous colitis. The more severe the inflammation and fluid loss, the greater the risk of acute kidney injury, ileus, megacolon, shock, and recurrent disease. A positive test does not automatically mean active CDI. Some people carry toxigenic C. difficile without symptoms. The diagnosis depends on compatible diarrhea or another clinical presentation, appropriate testing, and assessment for severity. This is why testing formed stool or screening an asymptomatic person can create a misleading result and lead to unnecessary treatment.