What are the diagnostic tests for abdominal pain (abdominal tenderness)?

From the Guidelines

When evaluating abdominal pain, a systematic approach is essential, beginning with a thorough history and physical examination, followed by laboratory tests and imaging studies, with the goal of identifying the underlying cause and providing appropriate patient care, as supported by the American College of Radiology Appropriateness Criteria 1.

Diagnostic Approach

The diagnostic approach to abdominal pain should be tailored to the patient's presentation, with urgent evaluation for severe, sudden-onset pain or signs of peritonitis.

• A thorough history should focus on pain characteristics, associated symptoms, and risk factors.
• Physical examination should include vital signs, abdominal inspection, auscultation for bowel sounds, percussion, and palpation to identify tenderness, guarding, or masses.
• Laboratory tests typically include complete blood count, comprehensive metabolic panel, urinalysis, and pregnancy test in women of childbearing age.

Imaging Studies

Imaging studies may include:

• Abdominal X-rays for obstruction or perforation
• Ultrasound for gallbladder or appendix issues
• CT scan for comprehensive evaluation of acute abdominal pain, as it has been shown to change the diagnosis and management plan in a significant proportion of patients 1
• MRI may be used in pregnant patients with abdominal pain when US is inconclusive, or in cases where CT is not feasible 1

Additional Tests

Additional tests like amylase/lipase for pancreatitis or stool studies for infectious causes may be indicated based on clinical suspicion.

Pain Management

Pain management should be provided as appropriate, as withholding analgesia does not interfere with diagnostic accuracy and addresses patient comfort, as emphasized by the World Journal of Emergency Surgery 1. The use of a step-up approach, starting with clinical and laboratory examination and progressing to imaging examinations, is recommended for the diagnosis of intra-abdominal infections, with CT and US being the primary imaging modalities, and MRI being considered in specific cases 1.

From the Research

Diagnostic Tests for Abdominal Pain

The diagnostic tests for abdominal pain (abdominal tenderness) include:

• Physical examination to assess the location and severity of pain 2
• Laboratory tests such as white blood count and C-reactive protein (CRP) to identify inflammatory markers 3, 4
• Imaging studies such as:
  • Ultrasonography to assess right upper quadrant pain 2
  • Computed tomography (CT) to assess right and left lower quadrant pain 2, 5
  • CT scanning with or without oral contrast to evaluate acute nontraumatic abdominal pain 5, 6
• Clinical evaluation to differentiate between urgent and nonurgent causes of abdominal pain 4

Imaging Studies

Imaging studies play a crucial role in the diagnosis of abdominal pain, with:

• CT scanning being the most sensitive and specific imaging modality for patients with acute abdominal pain 4, 5
• Ultrasonography being a preferred first imaging modality due to its lower downsides compared to CT 4
• Oral contrast not being necessary for most patients undergoing abdominal CT scanning for acute nontraumatic abdominal pain 6

Laboratory Tests

Laboratory tests such as:

• White blood count and CRP can help identify inflammatory markers and predict hospital admission 3
• Are insufficient to discriminate between urgent and nonurgent diagnoses on their own 4