Diverticulosis

Contributed by: Ahmar Sajjad, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030
Overview
  • Diverticulosis refers to acquired outpouchings of the colonic mucosa and submucosa due to high intraluminal pressure and focal areas of weakness in the colonic wall. They are most commonly found in the sigmoid colon and are associated with a low fiber diet.
Epidemiology
  • Diverticulosis is uncommon before the age of 30, with prevalence increasing with age thereafter. Risk factors include low-fiber diet, constipation, and a family history.
Morphology and Pathogenesis
  • A diverticulum in the gastrointestinal tract is an outpouching from the colon that communicates with the lumen of the gut. A diverticulum can be true (all three gut walls) or pseudo (only mucosa and submucosa) depending on which layers are involved. Although they can occur anywhere in the colon, the most common location is the sigmoid. They typically range from 0.5 to 1cm and are often found adjacent to the taenia coli.
  • Diverticuli are thought to be caused by increased intraluminal pressure, probably due to strong peristaltic contractions, which causes the inner layer of the colon to bulge through areas of focal weakness, likely at sites of vasculature.
Clinical Consequences
  • Overview
    • Diverticulosis is mostly asymptomatic and diagnosed incidentally on barium enema or colonoscopy. It may present with vague left lower quadrant discomfort, constipation, diarrhea or distention. In a small subset of patients diverticulosis may be complicated by rectal bleeding (hematochezia) or infection, presenting as diverticulitis.
  • Hematochezia
    • Although usually clinically insignificant and self-resolving, in roughly 5% of patients, bleeding can be severe, yielding a significant lower GI bleed. Diverticular bleeding is typically painless and the site of bleeding can be identified via colonoscopy, but may require surgical resection if persistent.
  • Diverticulitis
    • Diverticuli can be complicated by infection, thought to occur when a piece of feces, known as a fecalith, becomes impacted in the diverticulum. This often presents as LLQ pain, leukocytosis, and fever. Overall, the presentation is similar to appendicitis but occurs on the left side of the abdomen. Patients are treated with bowel rest and antibiotics. In some patients the infected diverticula can perforate leading to peritonitis, abscess formation, or a fistulization with the bladder.
Treatment
  • Treatment for diverticulosis is a high fiber diet and fiber supplements to increase stool bulk.