How to manage a patient with diverticulosis (inflammation of diverticula) presenting with mild and intermittent pain in the left lower quadrant?

Management of Diverticulosis with Mild Intermittent Left Lower Quadrant Pain

For a patient with known diverticulosis presenting with mild and intermittent left lower quadrant pain, obtain CT abdomen and pelvis with IV contrast to confirm the diagnosis and rule out complications, as clinical examination alone is unreliable with misdiagnosis rates of 34-68%. 1

Why CT Imaging is the Priority

• CT abdomen and pelvis with IV contrast is rated 8/9 (usually appropriate) by the American College of Radiology and has 98-99% diagnostic accuracy for diverticulitis and its complications. 2, 1, 3

• Clinical diagnosis based on symptoms alone is inadequate—the classic triad of left lower quadrant pain, fever, and leukocytosis is present in only 25% of diverticulitis cases. 1

• CT imaging is essential because it distinguishes between uncomplicated diverticulosis, uncomplicated diverticulitis, and complicated diverticulitis (abscess, perforation, fistula), which have completely different management strategies. 2, 1

• CT identifies alternative diagnoses that mimic diverticulitis, including colitis, inflammatory bowel disease, epiploic appendagitis, bowel obstruction, hernia, ovarian pathology, pyelonephritis, and urolithiasis. 2

Why IV Antibiotics Are NOT Appropriate Initially

• Antibiotics should NOT be started empirically in immunocompetent patients with suspected uncomplicated diverticulitis—they are only indicated for specific high-risk populations. 1, 3

• The World Journal of Emergency Surgery recommends conservative management WITHOUT antibiotics for immunocompetent patients with CT-confirmed uncomplicated diverticulitis. 1

• Antibiotics for uncomplicated diverticulitis should be reserved for: patients with persistent fever or chills, increasing leukocytosis, age >80 years, pregnancy, immunocompromised status (chemotherapy, high-dose steroids, organ transplant), or chronic medical conditions (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes). 3

• Starting antibiotics before imaging risks unnecessary antibiotic exposure, increased resistance, and fails to identify patients who actually need intervention (drainage, surgery) rather than antibiotics. 1

Why High-Fiber Diet is NOT Appropriate Acutely

• During acute symptomatic periods, patients do best on a clear liquid diet, NOT high-fiber diet. 4

• High-fiber diet is appropriate for asymptomatic diverticulosis or after resolution of acute symptoms to prevent disease progression and recurrence—not during active symptoms. 4, 5, 6

• Fiber supplementation (20-30 grams daily or psyllium) should be gradually increased only after the acute episode resolves. 4, 5

Management Algorithm After CT Results

If CT Shows Uncomplicated Diverticulitis (no abscess, perforation, or fistula):

• Conservative management with clear liquid diet, pain control with acetaminophen, and observation—NO antibiotics if immunocompetent. 1, 3

• Antibiotics (oral amoxicillin/clavulanic acid or cefalexin with metronidazole) for maximum 7 days ONLY if: immunocompromised, elderly (>80 years), pregnant, or chronic medical conditions. 1, 3

If CT Shows Complicated Diverticulitis with Small Abscess (<4 cm):

• Antibiotics alone for 7 days without drainage (ertapenem 1g q24h or eravacycline 1 mg/kg q12h). 1

If CT Shows Complicated Diverticulitis with Large Abscess (≥4 cm):

• Percutaneous CT-guided drainage PLUS antibiotics for 4 days. 1

If CT Shows Perforation with Diffuse Peritonitis:

• Emergency surgical consultation for laparotomy with colonic resection. 1, 3

Critical Pitfalls to Avoid

• Do not rely on clinical examination alone—symptoms overlap significantly with other conditions, and elderly patients present atypically with only 50% having lower quadrant pain. 1, 7

• Do not start antibiotics empirically without imaging—this leads to overtreatment in uncomplicated cases and undertreatment in complicated cases requiring drainage or surgery. 1, 3

• Do not recommend high-fiber diet during acute symptoms—this worsens pain and should only be implemented after symptom resolution. 4

• Do not order routine colonoscopy after CT-confirmed uncomplicated diverticulitis—colonoscopy is only indicated for age-appropriate cancer screening not yet performed, abnormal pericolic lymph nodes on CT, luminal mass on CT, or uncertain diagnosis. 1