From the Guidelines
The workup for diverticulosis should begin with a thorough history and physical examination, followed by imaging studies, with CT scan of the abdomen and pelvis with contrast being the preferred initial imaging modality to confirm the diagnosis and identify potential complications, as recommended by the American College of Physicians 1.
The initial evaluation of a patient with suspected diverticulosis or diverticulitis involves:
- A detailed history and physical examination to assess for abdominal symptoms and risk factors
- Laboratory tests, including complete blood count, comprehensive metabolic panel, and C-reactive protein to evaluate for inflammation
- Imaging studies, with CT scan of the abdomen and pelvis with contrast being the preferred initial imaging modality, as it has high sensitivity and specificity for diagnosing diverticulitis and identifying complications such as abscess or perforation 1
The use of CT scan with IV contrast is recommended for all patients with suspected diverticulitis to confirm the diagnosis and distinguish complicated from non-complicated disease, unless contraindicated due to severe kidney disease or contrast allergy, in which case alternative imaging modalities such as ultrasound or MRI may be considered 1.
For asymptomatic diverticulosis discovered incidentally, no specific treatment is needed, but patients should be counseled on a high-fiber diet (25-35g daily) and adequate hydration to reduce the risk of complications, with fiber supplements like psyllium (Metamucil) 1 teaspoon 1-3 times daily recommended if dietary fiber intake is insufficient 1.
The workup aims to confirm the diagnosis, assess severity, identify complications, and guide appropriate management, recognizing that diverticulosis itself is often asymptomatic and discovered incidentally during evaluations for other conditions, and that the risk of complications is highest with the first presentation 1.
From the Research
Diverticulosis Workup
- The initial laboratory workup for diverticulitis includes a complete blood count, basic metabolic panel, urinalysis, and C-reactive protein measurement 2.
- Computed tomography (CT) with intravenous contrast is the preferred imaging modality to confirm diagnosis and assess for complications of diverticulitis 2, 3, 4.
- CT is especially helpful in complicated diverticular disease and can guide therapeutic interventions 3, 5.
- Barium enema remains the gold standard for demonstrating the extent and severity of colonic diverticular disease, but CT has replaced it in many cases due to its ability to identify extracolonic extent of disease 5, 4, 6.
- Ultrasound and magnetic resonance imaging are also used in the diagnosis of diverticulitis, but CT remains the procedure of choice in the acute, symptomatic stage 4.
- Colonoscopy should not be performed during the flare-up, but should be considered six weeks after resolution of symptoms in patients with complicated diverticulitis who have not had a high-quality colonoscopy in the past year 2, 5.
Imaging Modalities
- CT scan is the most widely used examination for the diagnosis of diverticulitis due to its ability to demonstrate the extent of intramural inflammation and the degree of pericolic disease 3, 4.
- Barium enema is still used, especially in patients who are unable to have an adequate CT scan, those with suspected distant or diffuse abdominal abscess, those who are unresponsive to medical therapy, and those who are candidates for percutaneous drainage 6.
- Ultrasound is an alternative imaging modality, but its use is limited compared to CT and barium enema 5, 4.
Laboratory Tests
- A complete blood count is used to evaluate for signs of infection or inflammation 2.
- Basic metabolic panel is used to evaluate for signs of electrolyte imbalance or kidney dysfunction 2.
- Urinalysis is used to evaluate for signs of urinary tract infection or kidney disease 2.
- C-reactive protein measurement is used to evaluate for signs of inflammation 2.