|Severe||Episode of CDI with one or more specific clinical (fever, haemodynamic instability, respiratory failure which needs mechanical ventilation, signs and symptoms of peritonitis, signs and symptoms of colonic ileus), laboratory (marked leucocytosis, rise in serum creatinine and lactate, marked decrease of serum albumin), radiological (colon distension, colonic wall thickening) or endoscopic (pseudomembranous colitis), symptoms and signs of severe colitis or complicated course of disease|
|Recurrent||When CDI recurs within 8 weeks after the onset of a previous episode, provided the symptoms from the previous episode resolved after completion of initial treatment. It is not feasible to distinguish recurrence due to relapse (renewed symptoms from already present CDI) from recurrence due to reinfection in daily practice|
|Refractory||CDI that is unresponsive to the antimicrobial treatment, namely persistence of diarrhoea with CD toxin positive or persistent diarrhoea with toxin negative in the absence of other possible causes of diarrhoea (eg, IBS, IBD, non-CDI antibiotic-associated diarrhoea)|
CDI, Clostridium difficile infection; ESCMID, European Society for Microbiology and Infectious Disease.