What is the gold standard for diagnosis of diverticulosis and diverticulitis?

From the Guidelines

The gold standard for diagnosis of diverticulosis and diverticulitis is colonoscopy and computed tomography (CT) scan, respectively. Colonoscopy allows direct visualization of diverticula in the colon, making it the definitive test for diagnosing diverticulosis, though it should be performed when the patient is not experiencing acute inflammation. For acute diverticulitis, CT scan with intravenous and oral contrast is the preferred diagnostic method as it can identify inflamed diverticula, bowel wall thickening, fat stranding, and potential complications such as abscesses or perforations with high sensitivity and specificity (approximately 94-99%) 1.

Key Points for Diagnosis

• CT scanning is highly accurate for diagnosing diverticulitis and can help differentiate it from other conditions with similar presentations like appendicitis or inflammatory bowel disease.
• The use of IV and oral contrast material may improve diagnosis of abscess by distinguishing from adjacent bowel 1.
• Unenhanced CT with oral contrast is less accurate than contrast-enhanced CT with oral contrast for the characterization of complications of diverticulitis but is superior to unenhanced CT without oral contrast 1.
• CT can predict unfavorable outcomes from acute diverticulitis, including longer hospitalization and the need for surgery 1.

Clinical Considerations

• Endoscopic procedures are typically avoided during acute diverticulitis due to the risk of perforation and are usually performed 4-6 weeks after resolution of acute symptoms to confirm diagnosis and rule out other conditions like colorectal cancer.
• While other imaging modalities like ultrasound or MRI may be used in certain situations (such as in pregnant patients or those with renal insufficiency), they generally don't provide the same diagnostic accuracy as CT for diverticulitis 1.
• The American College of Physicians suggests using abdominal CT imaging when there is diagnostic uncertainty in a patient with suspected acute left-sided colonic diverticulitis, managing most patients with acute uncomplicated left-sided colonic diverticulitis in an outpatient setting, and initially managing select patients with acute uncomplicated left-sided colonic diverticulitis without antibiotics 1.

From the Research

Diagnosis of Diverticulosis and Diverticulitis

• The gold standard for diagnosis of diverticulitis is computed tomography (CT) with intravenous contrast 2, 3, 4, 5.
• CT is used to diagnose the first occurrence of diverticulitis and to assess the severity of symptoms, such as perforation or abscesses 6.
• Colonoscopy is recommended for all patients with complicated diverticulitis 6 weeks after CT diagnosis of inflammation, and for patients with uncomplicated diverticulitis who have suspicious features on CT scan or who otherwise meet national bowel cancer screening criteria 6.
• The Diverticular Inflammation and Complication Assessment (DICA) endoscopic classification is a predictive tool in managing diverticular disease, considering 10 different parameters to assess the severity of the disease 4, 5.

Imaging Methods

• Multidetector computed tomography (MDCT) is the current diagnostic gold standard for the imaging evaluation of diverticulitis 3.
• Magnetic resonance imaging (MRI) may have a role in the evaluation of diverticulitis, but its integration is still being investigated 3.
• Point-of-care ultrasound may become more important for initial diagnosis and follow-up assessment of diverticulitis 3.
• Intestinal ultrasonography (IUS) has been shown to have the same sensitivity as CT for the diagnosis of acute diverticulitis, with the advantage of being less expensive, non-invasive, and easily accessible 4.