What diagnostic tests are used to diagnose diverticulitis?

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Last updated: June 5, 2025View editorial policy

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From the Guidelines

Diagnosing diverticulitis typically involves a combination of clinical evaluation and imaging studies, with CT scan of the abdomen and pelvis being the gold standard due to its high sensitivity and specificity, as reported by 1. The most common diagnostic tests include:

  • Complete blood count (CBC) to check for elevated white blood cells indicating infection
  • Urinalysis to rule out urinary causes of pain
  • C-reactive protein or erythrocyte sedimentation rate to assess inflammation levels Imaging is crucial in diagnosing diverticulitis, and the choice of imaging modality depends on the patient's condition and availability of resources. Some key points to consider when choosing an imaging modality include:
  • CT scan of the abdomen and pelvis has a high sensitivity and specificity for diagnosing diverticulitis, as reported by 1
  • Ultrasound may be used as an initial test, especially in pregnant patients or those who cannot undergo CT, though it is less sensitive, as suggested by 1
  • MRI can be used as an alternative to CT, particularly for patients who cannot receive contrast or radiation, as reported by 1
  • Colonoscopy is generally avoided during acute episodes due to perforation risk but may be performed 6-8 weeks after resolution to rule out other conditions like colorectal cancer These tests collectively help clinicians confirm the diagnosis of diverticulitis and determine its severity, which guides appropriate treatment decisions ranging from outpatient antibiotics to surgical intervention for complicated cases, as discussed in 1 and 1. In terms of specific recommendations, CT scan of the abdomen and pelvis with oral and intravenous contrast is highly accurate for diagnosing diverticulitis, with a sensitivity and specificity of 95%, as reported by 1. However, in patients with contraindications to IV contrast material, unenhanced CT can be used, as reported by 1. Ultimately, the choice of diagnostic test should be based on the individual patient's needs and circumstances, and should be guided by the most recent and highest quality evidence, such as the study by 1.

From the Research

Diagnostic Tests for Diverticulitis

The diagnosis of diverticulitis involves a combination of clinical evaluation, laboratory tests, and imaging studies. The following are some of the diagnostic tests used to diagnose diverticulitis:

  • Complete blood count (CBC) to check for signs of infection or inflammation 2, 3
  • Basic metabolic panel (BMP) to evaluate kidney function and electrolyte levels 2, 3
  • Urinalysis to check for urinary tract infection or other abnormalities 2, 3
  • C-reactive protein (CRP) measurement to assess the level of inflammation 2, 3
  • Computed tomography (CT) scan with intravenous contrast to confirm the diagnosis and assess the extent and severity of the disease 2, 4, 3, 5, 6
  • Ultrasound to evaluate the bowel and detect any complications 5, 6
  • Magnetic resonance imaging (MRI) as a radiation-free alternative to CT scan 5, 6
  • Colonoscopy to evaluate the colon and detect any other abnormalities, typically performed 6 weeks after resolution of symptoms 2, 4, 3

Imaging Studies

Imaging studies play a crucial role in the diagnosis and management of diverticulitis. The choice of imaging study depends on the clinical presentation and the suspected severity of the disease.

  • CT scan is the most commonly used imaging study for diverticulitis, as it can accurately diagnose the condition and detect any complications 2, 4, 3, 5, 6
  • Ultrasound and MRI are alternative imaging studies that can be used in certain situations 5, 6
  • Barium enema is no longer commonly used for the diagnosis of diverticulitis, as it has been largely replaced by CT scan 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Diagnosis and management of acute diverticulitis.

American family physician, 2013

Research

Diverticular Disease: Rapid Evidence Review.

American family physician, 2022

Research

The management of diverticulitis: a review of the guidelines.

The Medical journal of Australia, 2019

Research

Diagnostic imaging for diverticulitis.

Journal of clinical gastroenterology, 2008

Research

Imaging update: acute colonic diverticulitis.

Clinics in colon and rectal surgery, 2009

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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