Spectrum: Local Antimicrobial Stewardship, for Island Health

Diverticulitis

Refers to acute inflammation and subsequent infection of intestinal diverticula, usually of the sigmoid colon, affecting ~5% of patients with diverticulosis

Diagnostic Pearls

Surgical/gastroenterology consultation for frank perforation, obstruction or fistula and refractory disease

Significant laboratory abnormalities may be absent

Blood cultures in severely ill and health care associated complicated infections; intra-operative cultures not needed unless hospital acquired or significant antibiotic exposure

Procalcitonin (PCT) not usually useful

If diarrhea (~25%), GPMP can be used to rule out other infectious etiologies (e.g. CDI, Salmonella spp.) but is unnecessary if diverticulitis is clear on imaging

Presence of colonic flora on urine culture suggests a colo-vesical fistula

Empiric Therapy

Outpatient

Uncomplicated disease and absence of:

  • severe pain or diffuse peritonitis

  • significant SIRS (two or more of: Temperature >38°C or <36°C; Heart rate >90/min; Respiratory rate >20/min; White blood cell count >12,000/mm3 or <4,000mm3)

  • intolerance of oral intake

  • previous treatment failure

  • multiple co-morbidities

  • significant immunosuppression

Uncomplicated

Infection not extending beyond the diverticula

Complicated

Presence of frank perforation, phlegmon, abscess, obstruction or fistula

Pre-operative fecal peritonitis

Bacteremia from diverticulitis as a source

Microbiology

Usual Organisms

Enterobacteriaceae (E. coli, Klebsiella)

Enteric anaerobes (B. fragilis, Clostridium spp.)

Less Common Organisms

Streptococci

Enterococcus faecalis

Organisms of Interest in IAI

ESBLs in IAI

AmpC producing organisms or "SPICE" bacteria in IAI

Enterococci, particularly E. faecium and VRE in IAI

MRSA in IAI

Candida in IAI