What are the management and treatment options for left side abdominal pain?

Management of Left-Sided Abdominal Pain

Initial Diagnostic Approach

Use CT imaging with IV contrast when diagnostic uncertainty exists after clinical evaluation, as it provides 98-99% sensitivity and specificity for acute left-sided colonic diverticulitis, the most common serious cause of left lower quadrant pain in adults. 1

Key Clinical Features to Assess

• Location and character of pain: Focal left lower quadrant tenderness strongly suggests diverticulitis (82% of cases), while diffuse left-sided tenderness may indicate complicated disease or alternative diagnoses 2
• Systemic symptoms: Fever, chills, and rebound tenderness occur more frequently with acute colonic diverticulitis (40-52% of cases) compared to benign conditions like primary epiploic appendagitis (7-14%) 2
• Laboratory markers: Leukocytosis (WBC >15 × 10⁹ cells/L) and elevated CRP (>140 mg/L) indicate higher risk for complicated diverticulitis and predict need for antibiotics 1, 3
• Duration of symptoms: Pain lasting >5 days before presentation increases risk of progression to complicated disease 3

When CT Imaging is Essential

Order CT with IV contrast for patients with:

• Fever, rebound tenderness, or signs of peritonitis 1
• Leukocytosis or elevated inflammatory markers 1, 3
• Age >65 years with any concerning features 1
• Immunocompromised status 3
• Inability to exclude surgical emergencies clinically 1, 4

Management Based on CT Findings

Uncomplicated Diverticulitis (No Abscess, Perforation, or Peritonitis)

Most immunocompetent patients with uncomplicated diverticulitis do NOT require antibiotics—observation with supportive care is the preferred first-line approach. 1, 3

Outpatient management criteria:

• Able to tolerate oral fluids and medications 3
• Temperature <100.4°F 3
• Pain controlled with acetaminophen alone 3
• No significant comorbidities or frailty 1, 3
• Adequate home support 1, 3

Reserve antibiotics for patients with specific risk factors:

• Immunocompromised status (corticosteroids, chemotherapy, transplant) 1, 3
• Age >80 years 3
• Pregnancy 3
• CRP >140 mg/L or WBC >15 × 10⁹ cells/L 1, 3
• Persistent vomiting or inability to maintain hydration 3
• Fluid collection or longer segment of inflammation on CT 1, 3
• ASA score III or IV 3

Antibiotic regimens when indicated:

• Outpatient oral: Amoxicillin-clavulanate 875/125 mg twice daily OR ciprofloxacin 500 mg twice daily plus metronidazole 500 mg three times daily for 4-7 days 3
• Inpatient IV: Ceftriaxone plus metronidazole OR piperacillin-tazobactam, transitioning to oral as soon as tolerated 3
• Duration: 4-7 days for immunocompetent patients; 10-14 days for immunocompromised patients 3

Mandatory follow-up within 7 days, sooner if symptoms worsen 1, 3

Complicated Diverticulitis (Abscess, Perforation, or Peritonitis)

All patients require hospitalization, IV antibiotics, and surgical consultation. 1, 5

Management algorithm:

• Small abscesses (<4-5 cm): IV antibiotics alone may suffice 1, 3
• Large abscesses (≥4-5 cm): Percutaneous CT-guided drainage plus IV antibiotics 1, 5, 3
• Generalized peritonitis or sepsis: Emergent surgical consultation for possible resection 1, 5

Antibiotic regimens for complicated disease:

• Non-critically ill: Ciprofloxacin plus metronidazole OR amoxicillin-clavulanate 5
• Critically ill with adequate source control: Piperacillin-tazobactam 4g/0.5g every 6 hours 5
• Septic shock: Meropenem 1g every 6 hours by extended infusion 5
• Duration: 4 days after adequate source control in immunocompetent patients; up to 7 days in immunocompromised or critically ill patients 1, 5

Alternative Diagnoses to Consider

Primary epiploic appendagitis presents with focal left lower quadrant pain but typically lacks fever, rebound tenderness, and laboratory abnormalities—CT shows oval fatty mass with hyperattenuated ring sign (89% of cases) 2

In children with left-sided abdominal pain, carefully examine the testes in boys (risk of testicular torsion) and focus initial investigation on the urinary tract 6

Post-Acute Management

Colonoscopy 4-6 weeks after symptom resolution is recommended for patients with complicated diverticulitis or first episode in patients >50 years to exclude malignancy 5, 3

Prevention of recurrence:

• High-fiber diet (>22 g/day from fruits, vegetables, whole grains, legumes) 3
• Regular vigorous physical activity 3
• Maintain normal BMI 3
• Smoking cessation 3
• Avoid regular NSAID use when possible 3

Critical Pitfalls to Avoid

• Do not routinely prescribe antibiotics for uncomplicated diverticulitis in immunocompetent patients without risk factors—this contributes to antibiotic resistance without clinical benefit 1, 3
• Do not assume all patients require hospitalization—outpatient management is safe and cost-effective (35-83% savings) for appropriate candidates 1
• Do not delay CT imaging in elderly patients or those with atypical presentations, as they may present with minimal symptoms despite serious disease 1, 4
• Do not restrict nuts, seeds, or popcorn—these foods are not associated with increased diverticulitis risk 3
• Do not apply the "no antibiotics" approach to complicated diverticulitis—evidence for observation without antibiotics specifically excluded patients with abscesses or higher Hinchey stages 3