Diverticulae, sac-like protrusions of the bowel wall, occur throughout the small and large bowel. The presence of these lesions should be considered in patients with unexplained gastrointestinal bleeding, intestinal obstruction, acute abdomen, chronic abdominal pain, anemia, or malabsorption . Large bowel diverticula are more frequent and more often present with a complication.
This topic review will focus on small bowel diverticula with the exception of Meckel's diverticulum. (See "Diagnostic approach to lower gastrointestinal bleeding in children", section on 'Meckel's diverticulum'.) The epidemiology and pathophysiology of colonic diverticular disease, the treatment of diverticulitis, and diverticular bleeding are discussed separately. (See "Colonic diverticulosis and diverticular disease: Epidemiology, risk factors, and pathogenesis" and "Treatment of acute diverticulitis" and "Colonic diverticular bleeding".)
Small bowel diverticula occur most frequently in the duodenum where they are usually asymptomatic. In one retrospective review of 208 patients, diverticula were located in the duodenum in 79 percent, in the jejunum or ileum in 18 percent, and in all three segments in 3 percent .
Complications occurred in 46 percent of jejunoileal diverticula compared to only 13 percent of duodenal diverticula.
Duodenal diverticula have been found in 2 to 5 percent of patients undergoing barium studies of the upper gastrointestinal tract, and in 7 percent of a series of 1735 patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) . They can be either extraluminal or rarely intraluminal.
Extraluminal diverticula — The vast majority of duodenal diverticula are extraluminal. They tend to occur near the papilla of Vater; in one study, for example, 61 percent were within 2 cm of the papilla . They are thought to be acquired as a result of herniation through a defect caused by the entrance of large vessels.