What are the possible causes of intermittent left-sided abdominal pain in a female?

Intermittent Left-Sided Abdominal Pain in Females: Differential Diagnosis

In a female with intermittent left-sided abdominal pain, the most common causes are diverticulitis (especially if older), gynecologic pathology (if reproductive age), urolithiasis, colitis, and epiploic appendagitis, with CT abdomen/pelvis with IV contrast being the diagnostic test of choice in most acute presentations 1, 2.

Primary Diagnostic Considerations by Location

Left Lower Quadrant Pain

Colonic causes dominate:

• Diverticulitis - Most common in adults, particularly elderly patients 1, 2, 3

  • Characterized by prolonged (≥24 hours), moderate to severe pain localized to left lower abdomen 4
  • CT with IV contrast is the gold standard for diagnosis and complication assessment 1
  • Ultrasound can be first-line in select settings (requires high operator expertise with >500 examinations for competency) 1

• Colitis (infectious, inflammatory bowel disease) 2

• Fecal impaction 2

• Epiploic appendagitis - self-limited, can mimic diverticulitis 2, 5

• Perforated colon cancer 3

Urologic causes:

• Left urolithiasis - sharp, colicky pain radiating to groin 2, 6

Gynecologic causes (reproductive age women):

• Ovarian pathology (cysts, torsion) 2
• Pelvic inflammatory disease 6
• Ectopic pregnancy - must be excluded 6
• Pelvic congestion syndrome - dull, aching pain with sharp exacerbations, worsened by postural changes and walking; associated with postcoital ache and deep dyspareunia 7

Other causes:

• Spontaneous retroperitoneal or rectus sheath hemorrhage 2
• Abdominal wall hernias 5
• Iliopsoas syndrome - diagnosed by sonopalpation 5

Left Upper Quadrant Pain

When pain is in the LUQ, consider:

• Splenic pathology (infarct, abscess, hematoma, splenomegaly) 8
• Pancreatitis with extension 8
• Gastric or colonic pathology (splenic flexure) 8

Diagnostic Approach Algorithm

Step 1: Risk Stratification by Clinical Features

Immediate red flags requiring urgent imaging:

• Hemodynamic instability
• Peritoneal signs
• Fever with localized tenderness
• Reproductive age without confirmed pregnancy status

Key history points:

• Duration: Prolonged pain (≥24 hours) suggests diverticulitis 4
• Character: Sharp/colicky (urolithiasis) vs. dull/aching (pelvic congestion, diverticulitis)
• Exacerbating factors: Postural changes and walking (pelvic congestion 7); postcoital ache (gynecologic 7)
• Associated symptoms: Fever (infection/abscess), dysuria (urinary), vaginal discharge (gynecologic), diarrhea (colitis)
• Age: Diverticulitis more common in elderly; gynecologic causes in reproductive age

Step 2: Initial Laboratory Testing

Order based on clinical suspicion 6:

• Pregnancy test (mandatory in reproductive age females)
• Complete blood count, C-reactive protein (elevated in diverticulitis 1)
• Urinalysis (urolithiasis, UTI)
• Consider fecal calprotectin if chronic symptoms (64% positive in symptomatic uncomplicated diverticular disease 4)

Step 3: Imaging Selection

For acute left lower quadrant pain:

• CT abdomen/pelvis with IV contrast is the primary modality 1, 2, 6
  • Superior for diverticulitis diagnosis, complication detection, and alternative diagnoses 1
  • Identifies abscess, perforation, extraluminal air, and guides percutaneous drainage 1
  • Oral contrast may improve abscess characterization but unenhanced CT without oral contrast is least accurate 1

For reproductive age women with suspected gynecologic pathology:

• Transvaginal ultrasound first 1
• MRI without and with IV contrast if ultrasound inconclusive and patient pregnant 6

For suspected urolithiasis:

• CT without IV contrast (stone protocol) or point-of-care ultrasound 6

For left upper quadrant pain:

• CT abdomen/pelvis with IV contrast for splenic pathology, abscess 8
• MRI with IV contrast if splenic mass/infiltrative process suspected 8

Critical Pitfalls to Avoid

1. Missing ectopic pregnancy - Always obtain pregnancy test before imaging in reproductive age women 6

2. Assuming IBS in patients with diverticula - Severe, prolonged left lower quadrant pain (≥24 hours) indicates symptomatic uncomplicated diverticular disease, not IBS 4

3. Overreliance on ultrasound for diverticulitis in obese patients - Sensitivity drops significantly; CT preferred in United States practice 1

4. Unnecessary biphasic CT - Combining unenhanced and contrast-enhanced CT adds no value for diverticulitis 1

5. Operating on epiploic appendagitis - Self-limited condition that mimics diverticulitis; recognition prevents unnecessary surgery 5

6. Ignoring pelvic congestion syndrome - Consider in multiparous women with chronic pain, postcoital ache, and ovarian point tenderness (94% sensitive, 77% specific) 7

Evidence Quality Note

The 2023 ACR Appropriateness Criteria 1 represents the highest quality, most recent guideline evidence for left lower quadrant pain imaging, with strong consensus (A+ grade from 16-17 of 18 European experts) supporting ultrasound as first-line in select populations, though CT remains preferred in U.S. practice due to superior accuracy and operator-independence.