Background
Small intestinal diverticulosis refers to the clinical entity characterized by the presence of multiple saclike mucosal herniations through weak points in the intestinal wall. [1, 2, 3] Small intestinal diverticula are far less common than colonic diverticula. The singular form is diverticulum, and the plural form is diverticula.
Pathophysiology
The cause of this condition is not known. It is believed to develop as the result of abnormalities in peristalsis, intestinal dyskinesis, and high segmental intraluminal pressures.
The resulting diverticula emerge on the mesenteric border (ie, sites where mesenteric vessels penetrate the small bowel). Diverticula are classified as true and false. True diverticula are composed of all layers of the intestinal wall, whereas false diverticula are formed from the herniation of the mucosal and submucosal layers. Meckel diverticulum is a true diverticulum.
Diverticula can be classified as intraluminal or extraluminal. Intraluminal diverticula and Meckel diverticulum are congenital. Extraluminal diverticula may be found in various anatomic locations and are referred to as duodenal, jejunal, ileal, or jejunoileal diverticula.
Etiology
The following risk factors apply to acquired pseudodiverticula:
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Low-fiber diet
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High-fat diet
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Advancing age
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Heredity: No evidence indicates that heredity plays a role in the development of small bowel diverticula.
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Systemic sclerosis
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Visceral myopathy
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Visceral neuropathy
Epidemiology
United States
Duodenal diverticula are approximately five times more common than jejunoileal diverticula. The actual incidence of both types of diverticula is not known because these lesions are usually asymptomatic. The incidence at autopsy of duodenal diverticula is 6-22%. Jejunal diverticula are less common, with a reported incidence of less than 0.5% on upper gastrointestinal radiographs and a 0.3-1.3% autopsy incidence.
The international incidence parallels that of the United States.
Race-, sex-, and age-related demographics
No known racial predilection exists.
Duodenal diverticula occur in equal numbers of men and women, while a slight male preponderance exists in jejunoileal diverticula.
Most cases of duodenal diverticula are observed in patients older than 50 years, while jejunoileal diverticula are commonly observed in patients aged 60-70 years. Reports of this condition in young adults exist as well.
Prognosis
The prognosis is good even with complications.
Complications
Complications include the following:
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Chronic abdominal pain
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Diverticulitis
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Intestinal obstruction
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Intestinal hemorrhage
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Malabsorption
Small bowel diverticula are generally asymptomatic, with the exception of Meckel diverticulum.
Major complications include diverticulitis, gastrointestinal hemorrhage, intestinal obstruction, acute perforation, and pancreatic and/or biliary disease in duodenal diverticula. Mortality is influenced by patients' age, nature of complications, and timeliness of intervention.
Unusual complications associated with Meckel diverticulum that have been reported include intussusception within its own lumen, [4] formation of a hernia sac with its mesentery and band, [5] and axial torsion and gangrene. [6]
Patient Education
Patients should understand the benign nature of the disease and that no definitive cure for this entity exists. In addition, they should know where to seek help if complications develop.
For patient education resources, see the Digestive Disorders Center, as well as Diverticulosis and Diverticulitis.
