From the Guidelines
The most appropriate diagnostic test for left-sided abdominal pain is a CT scan with IV contrast, as it provides a detailed evaluation of all abdominal structures and is particularly useful for suspected diverticulitis, kidney stones, or splenic issues. This recommendation is based on the latest evidence from the American College of Physicians (ACP) guideline on the diagnosis and management of acute left-sided colonic diverticulitis, which suggests that clinicians use abdominal CT imaging when there is diagnostic uncertainty in a patient with suspected acute left-sided colonic diverticulitis 1.
The initial evaluation of left-sided abdominal pain typically begins with blood tests, such as complete blood count, comprehensive metabolic panel, lipase, and urinalysis, to assess for infection, inflammation, or organ dysfunction. Imaging studies are crucial, and abdominal ultrasound may be used as a first-line option for visualizing the left kidney, spleen, and pancreatic tail. However, CT scan with contrast is the preferred imaging modality for suspected diverticulitis, as it can confirm the diagnosis and distinguish complicated from non-complicated diverticulitis 1.
Additional tests may include upper endoscopy to examine the stomach and duodenum if upper GI causes are suspected, or colonoscopy to evaluate the descending and sigmoid colon for diverticular disease, inflammatory bowel disease, or malignancy. For suspected urological issues, a CT urogram or renal ultrasound may be performed. Specialized tests like HIDA scan for gallbladder function or endoscopic ultrasound for pancreatic evaluation may be necessary in certain cases. The selection of tests depends on the patient's clinical presentation, including pain characteristics, associated symptoms, medical history, and physical examination findings, allowing for a targeted diagnostic approach. The American College of Radiology (ACR) also recommends CT abdomen and pelvis with IV contrast as the initial imaging of left lower quadrant pain with suspected diverticulitis 1.
In terms of specific patient populations, such as the elderly, the use of CT-scan with IV-contrast is still recommended to confirm the diagnosis and distinguish complicated from non-complicated diverticulitis, although alternative diagnostic approaches like US, MRI, or CT-scan without IV-contrast may be considered in patients who cannot undergo CT-scan with IV-contrast 1.
Overall, the choice of diagnostic test for left-sided abdominal pain should be guided by the patient's clinical presentation and the suspected underlying cause, with CT scan with contrast being the preferred imaging modality for suspected diverticulitis.
From the Research
Diagnostic Tests for Left-Sided Abdominal Pain
The diagnostic tests for left-sided abdominal pain include:
- Complete blood count (CBC) to check for signs of infection or inflammation 2, 3
- Basic metabolic panel (BMP) to evaluate electrolyte levels and kidney function 2
- Urinalysis to check for urinary tract infections or kidney stones 2, 3
- C-reactive protein (CRP) measurement to assess inflammation 2, 3
- Computed tomography (CT) scan with intravenous contrast to confirm diagnosis and assess for complications of diverticulitis 2, 4, 3
- Ultrasonography to evaluate for conditions such as cholelithiasis, urolithiasis, or appendicitis 3
- Point-of-care ultrasonography to aid in the prompt diagnosis of several etiologies of acute abdominal pain 3
- Magnetic resonance imaging (MRI) in pregnant patients if ultrasonography results are inconclusive 3
Laboratory Tests
Laboratory tests play a crucial role in narrowing the differential diagnosis of left-sided abdominal pain. These tests include:
- Hepatobiliary markers to evaluate liver function 3
- Electrolytes to assess electrolyte levels 3
- Creatinine to evaluate kidney function 3
- Glucose to check for diabetes or hypoglycemia 3
- Lipase to evaluate for pancreatitis 3
- Pregnancy testing to rule out ectopic pregnancy in female patients 3
Imaging Studies
Imaging studies are chosen based on the location of pain and index of suspicion for specific etiologies. For left-sided abdominal pain, CT scan with intravenous contrast is often the preferred imaging modality 2, 4, 3. Ultrasonography may also be used to evaluate for conditions such as cholelithiasis, urolithiasis, or appendicitis 3.