Acute Diverticulitis¶

Michael Koenig

Background¶

Inflammation and/or infection of a diverticulum, a small out-pouching along wall of colon
Presence of colonic flora on urine culture or pneumaturia suggests colovesical fistula
Most pts with uncomplicated diverticulitis have significant improvement 2-3 days after antibiotics

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

Bowel rest vs. clear liquids (advance diet as tolerated)
PO or IV antibiotics: should cover GNRs and anaerobic organisms
Zosyn, cefepime + metronidazole, or meropenem (if high risk for organisms w/ESBL)
Cipro/flagyl if PO
If low risk and mild disease, may not need antibiotics
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
Colonoscopy after complete resolution of symptoms (6 – 8 weeks) to definitively rule out presence of underlying colorectal cancer (unless performed in last year)

Pts who fail to improve or deteriorate require repeat imaging
Abscess continue antibiotics & 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 rule out cancer
Fistula: Rarely heal spontaneously, require surgical correction
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 like uncomplicated diverticulitis
- Frank perforation:
  - Intraabdominal free air, diffuse peritonitis requires emergency surgery