Diverticulitis

Background

• Prevalence of diverticulosis 30% by age 60, >70% by age 85
• 70% of patients with diverticulosis remain asymptomatic
• 13% of diverticulitis is found in patients <40 yrs of age
• Diverticular disease is almost exclusively left-sided colon (USA) or right-sided (Asia)
• Pathogenesis
  • Erosion of diverticular wall by inspissated fecal material leads to microperforation
    • Most common pathogens are anaerobes, as well as gram-negative rods
• Diverticular bleeding (painless LGIB) is NOT associated with diverticulitis

Clinical Features

• LLQ abdominal pain
  • Asian patients may complain of RLQ or suprapubic pain
• Fever
• Leukocytosis
• Change in bowel habits: diarrhea (30%) or constipation (50%)
• Nausea/vomiting
• Anorexia

Differential Diagnosis

LLQ Pain

• Diverticulitis
• Kidney stone
• UTI
• Pyelonephritis
• Ectopic pregnancy
• Infectious colitis
• Inflammatory bowel disease (Crohn's Disease, Ulcerative Colitis)
• Inguinal hernia
• Mesenteric ischemia
• Epiploic appendagitis
• Mittelschmerz
• Ovarian cyst
• Ovarian torsion
• PID
• Psoas abscess
• Testicular torsion
• Appendicitis
• Abdominal aortic aneurysm
• Herpes zoster
• Endometriosis
• Colon cancer
• Irritable bowel syndrome
• Small bowel obstruction

Diagnosis

Work-Up

• Labs
  • CBC
  • Chemistry
  • LFTs
  • Lipase
  • UA
• Imaging
  • CT with IV and PO contrast
    • Sn 97%, Sp 100%

Evaluation

• Stable patient with history of confirmed diverticulitis does not require further diagnostic evaluation
  • 1st time episode or current episode different from previous requires diagnostic imaging

Treatment

• Antibiotics are aimed at treating Gram Negative organisms and Anerobes (Enterobacteriaceae, Pseudomonas aeruginosa, Bacteriodes sp., and Enterococci)

Uncomplicated

• Modified Hinchey Class 0
• Liquid diet and bowel rest are most important

Antibiotic Options:

• Metronidazole 500mg PO Q8hrs AND Ciprofloxacin 500mg PO BID x5days
• Amoxicillin/Clavulanate 875/125 PO Q8hrs x5days (or Augmentin XR 2 tablets BID [each tablet 1gm amoxicillin 62.5mg clavulanate])
• Trimethoprim/Sulfamethoxazole, one double-strength tablet bid, and Metronidazole 500 mg Q8h
• Moxifloxacin 400mg PO QDaily

Current research suggests that antibiotics may not be necessary in uncomplicated diverticulitis if patient receives sufficient bowel rest in coordination with medicine observation and close follow up.

Complicated

• Defined as having a phlegmon, abscess, stricture, obstruction, fistula, or perforation
• Bowel rest in coordination with antibiotics
• Surgical consult for drainage of abscess or further surgical intervention

Antibiotics Options:

• Ticarcillin/Clavulanate 3.1 g IV Q6h or
• Piperacillin/Tazobactam 3.375 g IV q6 hours x 7-10 days
• Ciprofloxacin 400 mg IV q12h and metronidazole 1 g IV Q12h
• Ampicillin 2 g IV Q6h and Metronidazole 500 mg IV q6h Plus (Gentamicin 7 mg/kg Q24h or Ciprofloxacin 400 mg IV Q12h)
• Imipenem 500 mg IV Q6h

Disposition

Admit

• All complicated diverticulitis
• Intractable nausea/vomiting
• Comborbid disease
• High WBC, high fever, elderly, immunocompromised
• Failed outpt therapy (worsening symptoms or CT findings within 6 weeks of initial episode)

Discharge

• Well-appearing, immunocompetent patients with uncomplicated disease
• Refer all newly-diagnosed patients for follow up colonoscopy in 6 weeks (CT cannot rule out carcinoma)
• Surgical referral should be made for all patients with 3rd episode of diverticulitis