Diverticulitis Investigations
The diagnosis of acute diverticulitis can usually be made on the basis of history and physical examination. Laboratory tests may be of help when the diagnosis is in question or to assess the severity of the disease.
Blood Tests
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However, the absence of leukocytosis does not rule out diverticulitis, as 20-40% of patients have a normal white blood cell count. This is particularly true in patients who are immunocompromised, in elderly patients, and in those with less severe disease.
Imaging
CT scan of the abdomen is considered the best imaging method to confirm the diagnosis and in cases where abscess formation/ phlegmon is suspected. It can be used to guide percutaneous drainage of an abscess. Peritonitis, fistula formation, and obstruction can also be assessed.
CT scans can help assess the disease severity, presence of complications, and clinical staging. In the acute setting, CT scans are safer than contrast studies. Sensitivity and specificity, especially with helical CT and colonic contrast, can be as high as 97%.
Possible CT findings include the following:
Endoscopy is not recommended in the acute setting given the risk of worsening diverticulitis and bowel perforation. After the diverticulitis has subsided, colonoscopy can be used to evaluate the extent of diverticulosis or to rule out a malignancy masquerading as a benign postinflammatory stricture.
- Hemoglobin level is important if the patient reports hematochezia.
- Blood cultures should be obtained prior to the administration of empiric parenteral antimicrobial therapy in patients who are severely ill or in those with complicated disease.
Imaging
CT scan of the abdomen is considered the best imaging method to confirm the diagnosis and in cases where abscess formation/ phlegmon is suspected. It can be used to guide percutaneous drainage of an abscess. Peritonitis, fistula formation, and obstruction can also be assessed.
CT scans can help assess the disease severity, presence of complications, and clinical staging. In the acute setting, CT scans are safer than contrast studies. Sensitivity and specificity, especially with helical CT and colonic contrast, can be as high as 97%.
Possible CT findings include the following:
- Pericolic fat stranding due to inflammation
- Colonic diverticula
- Bowel wall thickening,
- Soft tissue inflammatory masses
- Phlegmon and abscesses
Endoscopy is not recommended in the acute setting given the risk of worsening diverticulitis and bowel perforation. After the diverticulitis has subsided, colonoscopy can be used to evaluate the extent of diverticulosis or to rule out a malignancy masquerading as a benign postinflammatory stricture.