Diverticulitis

Definition

Diverticulitis is inflammation of one or more colonic diverticula, often due to microperforation, leading to abdominal pain and systemic symptoms.

Epidemiology

• Common in Western countries due to low-fiber diet
• Prevalence increases with age; rare <40 years, ~50% by age 60, >70% by age 80
• Slightly more common in males <50 years; females predominate >70 years
• Most cases involve the sigmoid colon
• Hospitalization rates higher for complicated cases

Etiology

• Fecal impaction or obstruction of diverticula
• Altered colonic motility
• Low-fiber diet leading to increased intraluminal pressure
• Genetic predisposition
• NSAID or corticosteroid use may increase risk of complications

Pathophysiology

• Herniation of mucosa and submucosa through muscular layer forms diverticula
• Fecalith or stasis → microperforation → local inflammation
• Bacterial overgrowth exacerbates inflammation
• Inflammatory cascade can extend to pericolic tissue, causing abscess or perforation
• Complications include fistula formation, obstruction, bleeding, or generalized peritonitis