Management of Suspected Diverticulitis Refractory to Fluid Diet

Diagnostic Evaluation

The American College of Surgeons recommends obtaining a CT scan with IV contrast immediately to confirm diverticulitis and identify complications such as abscess, perforation, or peritonitis, with a sensitivity of 98-99% and specificity of 99-100% for acute diverticulitis 2
CT findings persist despite antibiotic treatment and remain essential for diagnosis verification and complication assessment 1

The patient's failure to improve on fluid diet alone indicates either high-risk uncomplicated diverticulitis or complicated disease requiring antibiotics, with specific features that mandate antibiotic therapy including refractory symptoms or vomiting, CRP >140 mg/L or WBC >15 × 10⁹ cells/L, symptoms lasting >5 days, inability to maintain oral hydration, immunocompromised status, age >80 years, or significant comorbidities 1

For uncomplicated diverticulitis with high-risk features, initiate oral antibiotics for 4-7 days, with first-line treatment being Amoxicillin-clavulanate 875/125 mg twice daily, and alternative treatment being Ciprofloxacin 500 mg twice daily PLUS metronidazole 500 mg three times daily 1
For complicated diverticulitis, hospitalize immediately and initiate IV antibiotics, with options including Ceftriaxone PLUS metronidazole, or Piperacillin-tazobactam 1
For abscess <4-5 cm, continue IV antibiotics alone for 7 days, and for abscess ≥4-5 cm, arrange percutaneous CT-guided drainage PLUS IV antibiotics for 4 days after adequate source control 1

Switch from IV to oral antibiotics as soon as the patient tolerates oral intake, typically within 48 hours, to facilitate earlier discharge, with a total antibiotic duration of 4-7 days for immunocompetent patients and 10-14 days for immunocompromised patients 1

Re-evaluate within 7 days, or sooner if clinical condition deteriorates, and if symptoms persist after 5-7 days of appropriate antibiotic therapy, obtain repeat CT imaging to assess for complications requiring drainage or surgery 1