What is the cause of left lower quadrant (LLQ) abdominal pain, with laboratory results and ultrasound (US) findings?

From the Guidelines

For left lower quadrant (LLQ) abdominal pain evaluation, I recommend a comprehensive approach including complete blood count (CBC), comprehensive metabolic panel (CMP), urinalysis, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR), as well as an abdominal ultrasound to visualize the area of concern, as suggested by the most recent guidelines 1. This combination helps identify common causes of LLQ pain such as diverticulitis, inflammatory bowel disease, urinary tract infections, or gynecological issues in women. The CBC can detect infection or inflammation through elevated white blood cells, while CMP assesses organ function and electrolyte balance. Inflammatory markers (CRP and ESR) help quantify inflammation severity. Ultrasound provides real-time imaging without radiation exposure, allowing visualization of bowel wall thickening, abscesses, ovarian pathology, or kidney stones. Some key points to consider in the evaluation of LLQ pain include:

• The clinical presentation, which can guide the choice of imaging modality
• The potential for diverticulitis, which should be suspected in patients with the clinical triad of left lower-quadrant pain, fever, and leukocytosis
• The use of CT scan, which is the preferred test in evaluating clinically suspected diverticulitis, as it can evaluate the severity and extent of disease and identify complications 1
• The importance of considering gynecological causes in female patients, and adding a pregnancy test and pelvic examination as needed If these initial tests are inconclusive, further imaging like CT scan may be necessary, especially if diverticulitis is suspected, as it is the most useful examination for left lower quadrant pain and can guide appropriate management 1. It is also important to note that some patients with typical symptoms of diverticulitis and no evidence of complication may not require imaging, and can be treated medically without undergoing radiologic examinations 1. However, imaging can be helpful in evaluating the extent of disease and detecting complications, and should be considered on a case-by-case basis.

From the Research

Left Lower Quadrant Abdominal Pain

• Left lower quadrant (LLQ) abdominal pain is a common indication for imaging in the emergency department 2
• The most common causes of LLQ abdominal pain originate from the colon, including:
  • Diverticulitis
  • Colitis
  • Fecal impaction
  • Epiploic appendagitis
• Other causes of LLQ abdominal pain include:
  • Left-sided urolithiasis
  • Spontaneous hemorrhage in the retroperitoneum or rectus sheath

Laboratory Tests

• Basic metabolic panel (BMP) findings can have implications for nursing care 3
• BMP includes values such as:
  • Potassium
  • Chloride
  • Blood urea nitrogen
  • Creatinine
• Complete blood count (CBC) components can provide important pathophysiological evidence 4
• CBC can inform the plan of care and produce the best patient outcomes

Imaging

• Computed tomography (CT) is the preferred imaging modality in the emergent setting for LLQ abdominal pain 2
• Ultrasound (US) may also be used to evaluate LLQ abdominal pain, although CT is generally preferred 2