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 routine colonoscopy or imaging
- Symptomatic diverticulosis: also known as 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 presents as painless hematochezia unless associated with active diverticulitis; bleeding is more common with right-sided diverticula.
- Diverticular disease accounts for ~300,000 hospitalizations per year in the United States.
- Diverticulitis occurs in 1–2% of the general population and in 4% of patients with diverticulosis (1). Diverticular bleeding occurs in 3–5% of patients with diverticulosis.
- Prevalence of diverticulosis and the number of diverticula increase with age.
- Diverticulosis occurs in 20% of those aged 40 years, 60% of those aged 60 years, and 70% by the age of 80 years.
- Incidence of diverticulitis increased from 62 to 75/100,000 people from 1998 to 2005; largest increase in patients <45 years of age—mostly due to changes in diet
- Male = female overall; more common in men <65 years of age and more common in women aged >65 years
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 micro- 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.
- Though genetics may play a role, there is no known genetic pattern.
- Asian and African populations have lower overall prevalence but develop diverticular disease with adoption of a Western lifestyle.
- Age >40 years; low-fiber diet
- 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.
- High-fiber diet or nonabsorbable fiber (psyllium)
- Regular physical activity
Commonly Associated Conditions
Colon cancer, connective tissue diseases, obesity, IBS, and inflammatory bowel disease
There's more to see -- the rest of this topic is available only to subscribers.