ICU · GI & nutrition / infection

Severe Diarrhoea & C. difficile — Toxins, Severity & the Vancomycin/Fidaxomicin Era

Also known as C. difficile · Clostridioides difficile · Antibiotic-associated diarrhoea · Pseudomembranous colitis · Toxic megacolon · NAP1 · Ribotype 027 · Fidaxomicin · Oral vancomycin · Bezlotoxumab · Faecal microbiota transplant · FMT

The C. difficile is the key ICU cause of the severe diarrhoea — the antibiotic-associated (the clindamycin, the fluoroquinolones, the cephalosporins), the spore-forming, the toxin A and B producer, the hypervirulent NAP1 or ribotype 027. The spectrum: the diarrhoea to the pseudomembranous colitis to the toxic megacolon to the perforation. The severe (the WCC over 15, the AKI creatinine over 1.5 times, the hypoalbuminaemia, the ileus or the megacolon); the fulminant (the shock, the megacolon, the perforation). The diagnosis: the GDH plus the toxin (the two-step); the PCR detects the colonisation, not the active disease (the over-diagnosis). The treatment (IDSA 2021): the non-severe the fidaxomicin OR the oral vancomycin 125 mg QID; the severe the oral vancomycin; the FULMINANT the vancomycin 500 mg QID plus the IV metronidazole plus-or-minus the rectal vancomycin plus the surgery (the subtotal colectomy for the megacolon). The recurrence: the bezlotoxumab, the faecal microbiota transplant. The stop the antibiotics and the PPI; the soap-and-water hand hygiene (the alcohol gel does not kill the spores); the isolate.

Checked against its sources on 9 Oct 2026