Acute Diverticulitis

Acute Diverticulitis – Michael Koenig


  • Inflammation and/or infection of a diverticulum, a small out-pouching along wall of colon
  • Ddx: (see approach to abdominal pain)
  • Presence of colonic flora on Urine culture suggests colo-vesical fistula
  • Most pts w/ uncomplicated diverticulitis have significant improvement 2-3 d after IV abx



  • Lower abdominal pain (85% LLQ), tenderness to palpation on exam, N/V, low-grade fever, change in bowel habits (constipation or diarrhea)



  • CBC w/diff, CMP, Lipase, U/A, β - hCG
  • Imaging: CT abdomen/pelvis with oral and IV contrast
      • CT findings: localized bowel wall thickening (>4mm), paracolic fat stranding, presence of colonic diverticula



  • IVF, pain control
  • Bowel rest vs. clear liquids (advance diet as tolerated)
  • IV antibiotics: should cover GNRs and anaerobic organisms
      • Zosyn, cefepime + metronidazole, or meropenem (if high risk for organisms w/ESBL)
  • Continue IV abx until abdominal pain/tenderness is resolved (usually 3-5 days), then transition to oral: cipro + metronidazole or Augmentin to complete 10-14 d course
  • Criteria for discharge:
      • Resolution of vital sign abnormalities (fever, tachycardia, hypotension)
      • Resolution of severe abdominal pain
      • Improvement of leukocytosis
      • Able to tolerate oral diet
  • Colonoscopy after complete resolution of symptoms (6 – 8 weeks) to definitively rule out presence of underlying colorectal cancer (unless performed in last year)


Additional Information


  • Pts who fail to improve or deteriorate require repeat imaging
  • Abscess cont. Abx & Percutaneous drainage (if possible) for abscesses > 4 cm
      • Surgery if no improvement 2-3 days after drainage
  • Obstruction: radiographic differentiation between acute diverticulitis and colon cancer is difficult; thus surgical resection of bowel is needed to relieve obstruction and r/o cancer
  • Fistula: Rarely heal spontaneously, require surgical correction
  • Bladder (65%), vagina (25%), small bowel (7%), uterus (3%)
  • Perforation:
      • Microperforation (contained perforation):
        • Presence of small amount of air bubbles, but no oral contrast outside of colon on CT
        • Most treated with IV abx and bowel rest similar to uncomplicated diverticulitis
    • Frank perforation: 
      • Intraabdominal free air, diffuse peritonitis requires emergency surgery