What is the next step in evaluating left-sided flank pain after a negative computed tomography (CT) scan of the abdomen (abdomen)?

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From the Guidelines

When a CT scan of the abdomen is negative in a patient with left-sided flank pain, the next step should be a comprehensive clinical reassessment to determine the underlying cause, including a detailed history and physical examination, followed by targeted laboratory tests and additional imaging studies as needed, such as ultrasound or MRI, as suggested by recent guidelines 1.

Clinical Reassessment

This should include a detailed history focusing on pain characteristics, associated symptoms, and risk factors. A thorough physical examination is also crucial to identify any potential causes of the pain.

Laboratory Tests

Laboratory tests such as complete blood count, comprehensive metabolic panel, urinalysis, and inflammatory markers (ESR, CRP) should be ordered if not already done. These tests can help identify potential causes of the pain, such as infection or inflammation.

Additional Imaging Studies

Depending on the clinical suspicion, additional imaging studies may be warranted. For example, ultrasound can be used to evaluate for musculoskeletal or vascular causes, while MRI can provide better soft tissue visualization. A CT urogram may be necessary if urological pathology is suspected, as it can help identify stones or other abnormalities in the urinary tract, as noted in the guidelines for acute onset flank pain-suspicion of stone disease (urolithiasis) 1.

Specialist Consultation

Consultation with specialists like gastroenterology, urology, or gynecology (in female patients) may be necessary based on the evolving clinical picture. This is because left flank pain has numerous potential causes, including renal, gastrointestinal, musculoskeletal, and reproductive system disorders, some of which may not be readily apparent on a standard CT scan.

Importance of a Stepwise Approach

This stepwise approach is important because it allows for a thorough and systematic evaluation of the patient's symptoms, reducing the risk of missing a potential cause of the pain. By following this approach, clinicians can ensure that they are providing the best possible care for their patients, as supported by recent studies on the evaluation of acute onset flank pain 1.

From the Research

Next Steps in Evaluating Left-Sided Flank Pain

After a negative computed tomography (CT) scan of the abdomen, the next steps in evaluating left-sided flank pain may include:

  • Considering other potential causes of flank pain, such as nephrolithiasis, pyelonephritis, or other renal pathologies 2
  • Utilizing other imaging modalities, such as magnetic resonance imaging (MRI) or contrast-enhanced ultrasound (CEUS), to further evaluate the kidneys and surrounding structures 3
  • Evaluating for other potential causes of left-sided abdominal pain, such as primary epiploic appendagitis or colonic diverticulitis 4
  • Using point-of-care ultrasound (PoCUS) to assess for hydronephrosis or other renal causes of pain 5

Diagnostic Considerations

When evaluating left-sided flank pain, it is essential to consider a broad range of potential causes, including:

  • Renal pathologies, such as nephrolithiasis or pyelonephritis
  • Gastrointestinal pathologies, such as primary epiploic appendagitis or colonic diverticulitis
  • Other potential causes, such as musculoskeletal or vascular pathologies

Imaging Modalities

Various imaging modalities can be used to evaluate left-sided flank pain, including:

  • CT scans
  • MRI
  • CEUS
  • PoCUS Each modality has its strengths and limitations, and the choice of modality will depend on the specific clinical scenario and the potential causes being considered 3, 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Flank pain and hematuria is not always a kidney stone.

The American journal of emergency medicine, 2021

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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