• Single (diverticulum) or multiple (diverticula) colonic wall outpouchings from colonic muscle dysfunction, usually acquired
  • Sequence:
    • Insufficient amounts of dietary fiber cause diminished stool bulk
    • Increased colonic contractions to propel stool through colon cause increase in intraluminal pressure
    • Increased pressure forces mucosa and submucosa to herniate through muscularis propria at its weakest point, where vasa recta penetrate


  • Occurs anywhere in GI tract, although generally a colonic disease:
    • Left sided: 95% (Western countries)
    • Right sided: 70% (Asian countries)
    • Sigmoid colon most common site
  • Pseudodiverticula:
    • Outpouchings of mucosa and submucosa only
    • Most common form of colonic diverticula
    • True congenital diverticula (uncommon) contain all bowel wall layers
  • Common in Western society, owing to refined diet, and decreased fiber intake
  • Prevalence is age-dependent:
    • 50% by age 60, 70% by age 80
    • Affects men and women equally
  • Complications:
    • 70% are asymptomatic
    • <5% develop diverticulitis
    • 5–15% develop bleeding; obesity is a risk factor:
      • Bleeding stops spontaneously in 75% of cases
    • Inflammation (diverticulitis)
    • Massive arterial bleeding usually from right colon:
      • Fecalith (dry, hard stool) erodes through arterial branch
    • Perforation
    • Abscess
    • Obstruction

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