Description

Diverticulum (single) or diverticula (multiple) are outpouchings of the colonic wall. Diverticular disease is a spectrum of diseases impacting the entire GI tract (except the rectum):

• Asymptomatic diverticulosis: common incidental finding on colonoscopy or imaging
• Symptomatic diverticulosis: also called symptomatic uncomplicated diverticular disease (SUDD); recurrent abdominal pain attributed to diverticulosis without colitis or diverticulitis (1)
• Acute diverticulitis: diverticular disease with associated inflammation and/or infection
  • Uncomplicated diverticulitis: abdominal pain and leukocytosis without peritoneal signs or systemic toxicity
  • Complicated diverticulitis: secondary abscess formation, bowel obstruction, perforation, peritonitis, fistula, or stricture in the setting of diverticular inflammation
• Diverticular bleeding: accounts for >40% of lower GI bleeds; often painless hematochezia unless accompanied by active diverticulitis; bleeding is more common with right-sided diverticula.

Epidemiology

Etiology and Pathophysiology

Diverticula form at points of weakness along the intestinal wall where small blood vessels (vasa recta) penetrate through the muscular layer of the colon.

• Age-related degeneration of the mucosal wall; increased intraluminal pressure from dense, fiber-depleted stools; and abnormal colonic motility contribute to diverticulosis.
• Most right-sided diverticula are true diverticula (involves all layers of the colonic wall).
• Most left-sided diverticula are pseudodiverticula (outpouchings of the mucosa and submucosa only).
• Diverticulitis occurs when local inflammation and infection contribute to tissue necrosis with risk for mucosal microperforation or macroperforation.
• Alterations in intestinal microbiota contribute to chronic inflammation (1).
• Thinning of the vasa recta over the neck of the diverticula increases susceptibility to bleeding.
• Diverticular disease and irritable bowel syndrome (IBS) may represent the same disease continuum.

Risk Factors

• Age >40 years; low-fiber diet and high red-meat consumption
• Sedentary lifestyle, obesity, previous diverticulitis; risk rises with the number of diverticula.
• Smoking increases the risk of perforation (1).
• Risk of diverticular bleeding increases with NSAIDs, steroids, and opiate analgesics. Calcium channel blockers and statins protect against diverticular bleeding.

General Prevention

• High-fiber diet or nonabsorbable fiber (psyllium)
• Regular physical activity

Commonly Associated Conditions

Colorectal polyps, nonalcoholic fatty liver disease, hypothyroidism, arterial hypertension, colon cancer, connective tissue diseases, obesity, IBS, and inflammatory bowel disease