What management is recommended for suspected diverticulitis with mild to moderate LLQ pain beyond bowel rest and clear liquids, and when to initiate Augmentin (amoxicillin-clavulanate) and urgent CT abdomen?

Management of Suspected Diverticulitis with Mild to Moderate LLQ Pain

For mild to moderate left lower quadrant pain with suspected diverticulitis without fever, nausea, vomiting, or chills, a non-urgent CT scan is appropriate, and antibiotics (Augmentin) should be used selectively rather than routinely in immunocompetent patients.

Diagnostic Approach

Imaging Considerations

• CT scan timing: A non-urgent CT scan with IV contrast is appropriate for mild-moderate LLQ pain without systemic symptoms 1
  • The American College of Radiology rates contrast-enhanced CT as the most appropriate imaging study (rating 8/9) for suspected diverticulitis 1
  • Urgent CT is not necessary for mild symptoms without fever, nausea/vomiting, or signs of peritonitis 1

Risk Assessment

Before deciding on antibiotics, assess for risk factors that would warrant antibiotic therapy:

• Immunocompromised status
• Comorbidities or frailty
• Refractory symptoms or vomiting
• CRP >140 mg/L
• WBC >15 × 10⁹ cells/L
• Presence of fluid collection on CT
• Longer segment of inflammation on CT 1

Treatment Algorithm

Initial Management

1. Bowel rest/Clear liquid diet

   • Recommended during the acute phase of uncomplicated diverticulitis 1
   • Advance diet as symptoms improve 1

2. Antibiotic Decision Tree:

   • No antibiotics if:

     • Immunocompetent patient
     • Mild symptoms
     • No fever/systemic symptoms
     • Normal or mildly elevated inflammatory markers 1

   • Start Augmentin (amoxicillin-clavulanate) if:

     • Any risk factors listed above
     • Evidence of complicated diverticulitis on imaging
     • Immunocompromised status 1

Antibiotic Regimen (if indicated)

• Outpatient: Amoxicillin-clavulanate (Augmentin) 875/125 mg orally twice daily for 4-7 days 1, 2
• Take at the start of a meal to minimize gastrointestinal intolerance 2

Follow-up Recommendations

• If symptoms persist or worsen after 48-72 hours, reassess with possible CT imaging 3
• Consider colonoscopy 6-8 weeks after resolution of symptoms, particularly if this is a first episode or if complicated diverticulitis was diagnosed 3

Important Caveats

• Clinical diagnosis alone is unreliable: Studies show misdiagnosis rates between 34-68% without imaging 3

• Watchful waiting: Recent evidence suggests antibiotics can be safely withheld in selected patients with uncomplicated diverticulitis 1

• Warning signs requiring immediate medical attention:

  • Development of fever
  • Worsening abdominal pain
  • Inability to tolerate oral intake
  • Signs of peritonitis (rigid abdomen, rebound tenderness)

• Pitfall to avoid: Don't assume all LLQ pain is diverticulitis. CT helps exclude other conditions like ischemic colitis, inflammatory bowel disease, or malignancy 1

Remember that while most cases of mild diverticulitis can be managed conservatively, close monitoring for clinical deterioration is essential, as approximately 5% of uncomplicated cases can progress to complicated diverticulitis 1.