From the Guidelines
Diverticulosis is best assessed through a combination of clinical evaluation and imaging studies, with CT scanning with contrast being the most useful examination for patients with suspected colonic diverticulitis due to its reproducibility and superior diagnostic accuracy 1. The assessment of diverticulosis should start with a detailed history focusing on abdominal pain patterns, changes in bowel habits, and any history of complications like bleeding or inflammation.
- A physical examination may reveal tenderness in the left lower quadrant but is often normal in uncomplicated diverticulosis.
- Laboratory tests are typically normal in uncomplicated diverticulosis but may show elevated inflammatory markers during active diverticulitis.
- The most definitive diagnostic test is a colonoscopy, which allows direct visualization of the colonic diverticula (small pouches that form in the colon wall) 1.
- CT scanning with contrast is another excellent option, particularly in acute settings or when complications are suspected, with a diagnostic accuracy of 98% 1.
- Barium enema studies can also identify diverticula but are less commonly used today.
- When assessing for diverticulosis, it's essential to note that many patients are asymptomatic, with the condition often discovered incidentally during routine screening colonoscopies.
- Diverticulosis develops due to increased intraluminal pressure in the colon combined with weakening of the colonic wall, often related to age, low-fiber diet, and possibly genetic factors, making these important considerations in the assessment process.
- CT diagnosis of uncomplicated acute diverticulitis in the emergency department can prevent unneeded hospital admission, as most colonic diverticulitis is uncomplicated and can be managed with outpatient antibiotics 1.
- IV contrast material is commonly used to improve the characterization and detection of subtle bowel wall abnormalities and complications of diverticulitis, but unenhanced CT is more accurate than clinical evaluation alone and can be used in patients with contraindication to IV contrast material 1.
From the Research
Assessment Methods for Diverticulosis
- Colonoscopy: a diagnostic and therapeutic tool for evaluating asymptomatic diverticulosis, segmental diverticular disease-associated colitis, and acute diverticulitis 2
- Flexible sigmoidoscopy: a viable alternative to colonoscopy for follow-up investigations in patients with left-sided diverticulitis, especially when no worrying radiological findings are present 3, 4
- Computed Tomography (CT): the procedure of choice in the acute, symptomatic stage of diverticulitis, used to establish the diagnosis, extent, and severity of the disease, as well as detect any complications 5
- CT-colonography (CTC): a less painful and unpleasant alternative to colonoscopy, with good accuracy in detecting diverticulosis, but poor detection accuracy for small polyps 6
Diagnostic Imaging
- Ultrasound, barium enema, CT, and magnetic resonance imaging are commonly used examinations for the diagnosis of diverticulitis 5
- CT has replaced barium enema as the primary imaging modality due to its ability to identify extracolonic extent of disease 5
Endoscopy After Acute Sigmoid Diverticulitis
- Current guidelines suggest colonoscopy after CT-confirmed acute diverticulitis to rule out colorectal cancer (CRC) 4
- Flexible sigmoidoscopy may be a sufficient alternative to full colonoscopy in the absence of red flag features, offering advantages such as being quicker, cheaper, and safer, with no need for full bowel preparation or IV sedation 4