Table 2.

Differentiating Clostridium difficile infection and inflammatory bowel disease

Features	Isolated CDI	CDI and IBD
Setting	Often hospital acquired	Often community-acquired
Risk factors	Antibiotic exposure prior to infection common	Many patients lacking of history of antibiotic exposure
	Immunomodulator and corticosteroid use	Immunomodulator and corticosteroid use playing even a greater role
	Increasing age	Increasing age
		Risk greater with ulcerative colitis than Crohn’s disease, more with colonic involvement than small bowel disease
Clinical features	Usually watery diarrhea	May be bloody or mucous diarrhea
Outcome	Short term complications including toxic megacolon, colonic perforation, and peritonitis with sepsis	Short term complications including toxic megacolon, colonic perforation, and peritonitis with sepsis similar to patients without IBD
		Hospitalization costs and length of stay variable in studies
		Increased mortality in some studies
		Risk of colectomy unclear
		Long term outcome unclear, increased hospitalizations and escalation in medication use and colectomy rates reported with retrospective data
Diagnosis	ELISA testing for toxins	ELISA testing may be less sensitive
Endoscopy and histology	Pseudomembranes common	Pseudomembranes rare
Treatment	Metronidazole for mild to moderate severity	? Vancomycin for any hospitalized IBD patient
	Vancomycin for severe disease
Recurrence	20% after the first episode of CDI	Rates highly variable 10%-58%, may be higher
Extra-colonic gastrointestinal manifestations	Small bowel can be affected	Most cases of small bowel involvement in IBD patients
		Pouchitis can also be seen

IBD: Inflammatory bowel disease; ELISA: Enzyme linked immunoassay; CDI: Clostridium difficile infection.