Laboratory Studies
Laboratory tests have limited value in diagnosing small bowel diverticulosis. The following tests may be indicated:
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CBC count: Elevated white blood cell (WBC) count may occur in diverticulitis. Hematocrit may drop following significant acute or chronic blood loss.
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Chemistry: Liver chemistries, serum amylase and lipase levels are performed only if indicated by clinical presentation to exclude other differential diagnoses.
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Urinalysis: Urinalysis may be indicated to rule out urinary tract infection.
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Blood culture: This is useful in patients presenting with fever, diverticulitis, intestinal perforation, and abscess to exclude septicemia.
Imaging Studies
Although small bowel diverticulitis is not routinely considered in the differential diagnosis of an acute abdomen, prospective diagnosis by imaging is important. It can result in conservative treatment and eliminate the possibility of unnecessary exploratory laparotomy. [8]
Plain abdominal radiographs and/or chest radiographs demonstrate evidence of perforation, including air under the diaphragm; free peritoneal air; evidence of intestinal obstruction; or evidence of ileus, including multiple air-fluid levels and bowel dilatation.
Abdominal computed tomography (CT) scanning with contrast provides more information in complicated as well as uncomplicated cases. Phlegmon can be identified, especially in the retroperitoneal space, providing the initial clue to the possibility of small intestinal diverticular disease. [9, 10]
In a study of 7 patients with surgically confirmed diagnoses of small bowel diverticulosis/diverticulitis, Mansoori et al found that small bowel diverticulitis demonstrates characteristic magnetic resonance enterography/enteroclysis (MRE) imaging features to distinguish it from more common diseases. The characteristic imaging features included asymmetric, focal mesenteric, and mural inflammation, as well as the presence of multiple diverticula. [11]
A double contrast barium meal and enteroclysis is useful in diagnosis but is contraindicated in acute diverticulitis or perforation.
Double balloon enteroscopy may be useful in diagnosing jejunal diverticulosis; it may also be used preoperatively to diagnose Meckel diverticulum. [12] This modality may reveal an incidental finding or be used for diagnostic purposes. As double balloon enteroscopy has interventional capacity, it may be used to arrest gastrointestinal (GI) bleeding from complicated diverticular disease.
Capsule endoscopy has been used in incidental diagnosis as well as an indication for other GI lesions. This imaging modality involves swallowing a capsule with a battery source, camera, and broadcasting capacity. The signals/images are sent to a device worn on a belt and recorded for further evaluation. The pill passes in the feces and does not need to be retrieved.
Capsule endoscopy should be avoided in acute diverticulitis, perforation, or small bowel obstruction. However, a retrospective review of 31 patients by Yang et al appeared to suggest that this modality may be safe and effective in the visual identification of the etiology of subacute small bowel obstruction, particularly in cases of suspected intestinal tumors or Crohn disease not found with routine studies. [13] Of the 31 cases, the investigators found that capsule endoscopy provided a definitive diagnosis in 12 (38.7%), including 4 Crohn disease, 2 carcinomas, and 1 each of intestinal tuberculosis, ischemic enteritis, abdominal cocoon, intestinal duplication, diverticulum, and ileal polypoid tumor. The procedure did not cause acute small bowel obstruction in any patients, but the capsule was retained in 3 (9.7%) patients either due to Crohn disease (n = 2; retrieved at surgery) or tumor (n = 1; spontaneously passed with medical therapy within 6 mo). [13]
Other studies
Bleeding scan is used to determine the site of bleeding if the patient is hemodynamically stable. It is helpful in localizing bleeding sites, detecting bleeding as slow as 0.5 mL/min.
Mesenteric angiography is used for brisk hemorrhages, at least 1 mL/min, to identify the bleeding site and offers the opportunity for mesenteric occlusion therapy. The catheter may be left in place for ease of identification at surgery.
For more information, see Meckel Diverticulum Imaging.
Procedures
Esophagogastroduodenoscopy yields 9-20% on all upper gastrointestinal endoscopy. Endoscopic procedures are generally contraindicated in acute diverticulitis. Colonoscopy may be useful in excluding other causes. The jejunoileal diverticulum is not accessible by colonoscopy and esophagogastroduodenoscopy (EGD).
Endoscopic retrograde choledochopancreatography demonstrates periampullary diverticula.
Enteroscopy may be used to evaluate the jejunum and ileum with either the Push or Sonde types of enteroscopy. Experience is of great importance in recognizing these lesions.
Double balloon enteroscopy can help identify the presence of disease and also the cause of any obscure bleeding. This procedure can also therapeutically intervene at the identified site of bleed. In this procedure, the small bowel is pleated proximally on the scope to advance distally through the small bowel.
