What is the appropriate diagnosis, workup, and management for a patient presenting with pain localized to the hepatic flexure (upper right transverse colon) suggestive of diverticulitis?

Right-Sided (Hepatic Flexure) Diverticulitis: Diagnosis, Workup, and Management

Diagnostic Confirmation

Contrast-enhanced CT of the abdomen and pelvis is mandatory for any patient with suspected right-sided diverticulitis, because clinical examination alone misdiagnoses 34–68% of cases and the presentation mimics acute appendicitis in the majority of patients. 1, 2

• Right-sided diverticulitis occurs in only 1.5% of all diverticulitis cases in Western populations, but is more common in Asian countries where it can outnumber left-sided disease. 3, 4, 5
• The hepatic flexure and ascending colon are the second most common sites after the cecum for right-sided diverticulitis, typically presenting in younger patients (mean age 40–50 years) compared to left-sided disease. 3, 4
• CT achieves 98–99% sensitivity and 99–100% specificity for diagnosing diverticulitis and reliably distinguishes it from appendicitis, ileitis, and gynecologic pathology. 1, 6

Key Clinical Differentiators from Appendicitis

Right-sided diverticulitis patients typically lack prodromal symptoms (anorexia, nausea preceding pain), have maximal tenderness lateral to McBurney's point rather than at McBurney's point, and demonstrate milder leukocytosis (≈11,000/mm³) with a higher lymphocyte fraction (≈18%) compared to appendicitis patients. 7

• Appendicitis presents with prodromal symptoms in >80% of cases, whereas right-sided diverticulitis rarely does. 7
• Maximal tenderness lateral to McBurney's point occurs in ≈20% of right-sided diverticulitis but is rare in appendicitis. 7
• Appendicitis typically produces leukocytosis >13,000/mm³ with >79% segmented neutrophils, whereas right-sided diverticulitis shows WBC ≈11,000/mm³ with ≈74% segmented forms. 7

Management Algorithm

Uncomplicated Right-Sided Diverticulitis (No Abscess, Perforation, or Peritonitis)

The principles of diagnosis and treatment for acute right-sided colonic diverticulitis (ARCD) are identical to those for left-sided disease; all WSES guidelines for left-sided diverticulitis apply equally to right-sided presentations. 3

• For immunocompetent patients with uncomplicated right-sided diverticulitis, observation with supportive care (clear liquid diet, acetaminophen for pain, oral hydration) without routine antibiotics is the first-line approach. 1, 8
• Outpatient management is appropriate when the patient can tolerate oral intake, has temperature <100.4°F, pain score <4/10 controlled with acetaminophen, no significant comorbidities, and reliable follow-up within 7 days. 1, 8

Reserve antibiotics for patients with any of the following high-risk features:

• Persistent fever >100.4°F or chills despite supportive care 1, 8
• Refractory symptoms, vomiting, or inability to maintain oral hydration 1, 8
• C-reactive protein >140 mg/L or WBC >15 × 10⁹/L 1, 8
• Immunocompromised status (chemotherapy, high-dose steroids, organ transplant) 1, 8
• Age >80 years, pregnancy, or ASA physical status III–IV 1, 8
• CT findings of pericolic fluid collection or extensive inflammation 1, 8

When antibiotics are indicated, use:

• Outpatient oral regimen (4–7 days): Amoxicillin-clavulanate 875/125 mg twice daily OR Ciprofloxacin 500 mg twice daily + Metronidazole 500 mg three times daily 1, 8
• Inpatient IV regimen: Ceftriaxone + Metronidazole OR Piperacillin-tazobactam, transitioning to oral within 48 hours when tolerated 1, 8
• Duration: 4–7 days for immunocompetent patients; 10–14 days for immunocompromised patients 1, 8

Complicated Right-Sided Diverticulitis

Small abscesses (<4–5 cm) require hospitalization with IV broad-spectrum antibiotics (covering gram-negative and anaerobic organisms) for 7 days without drainage. 3, 1

Large abscesses (≥4–5 cm) require CT-guided percutaneous drainage plus IV antibiotics; continue antibiotics for 4 days post-drainage in immunocompetent patients, up to 7 days in immunocompromised or critically ill patients. 3, 1

Generalized peritonitis or sepsis mandates emergent surgical consultation for source control (resection with primary anastomosis or Hartmann's procedure) plus immediate IV broad-spectrum antibiotics. 3, 1

• Laparoscopic right hemicolectomy with primary anastomosis can be performed in experienced centers for complicated cases requiring surgery. 3
• The percentage of complications requiring surgery is actually higher in left-sided diverticulitis than in right-sided disease, making non-operative management even more successful for ARCD. 3

Diagnostic Confirmation After Acute Phase

Colonoscopy or barium enema should be performed 6–8 weeks after symptom resolution to confirm the presence of right-sided diverticula and exclude alternative diagnoses (colon cancer, Crohn's disease, cecal pathology). 5

• This delayed endoscopic confirmation is particularly important in right-sided diverticulitis because the diagnosis is often presumptive on initial CT and the differential diagnosis is broader than for left-sided disease. 5
• Colonoscopy during the acute inflammatory phase carries high perforation risk and should be deferred. 1, 5

Critical Pitfalls to Avoid

• Do not proceed to emergency appendectomy based on clinical presentation alone; CT confirmation prevents unnecessary surgery in ≈20% of cases initially suspected to be appendicitis. 5, 7
• Do not assume all right-sided diverticulitis requires antibiotics; the same selective antibiotic stewardship principles from left-sided disease apply equally to ARCD. 3, 1
• Do not overlook surgical consultation in the acute setting; even though most cases resolve with medical management, surgical evaluation helps exclude appendicitis and ensures appropriate escalation if complications develop. 3, 5
• Do not skip delayed colonoscopy; right-sided presentations have a broader differential diagnosis and require endoscopic confirmation of diverticula after recovery. 5

Special Considerations for Hepatic Flexure Location

• Transverse colonic diverticulitis (including hepatic flexure) accounts for <1% of all colonic diverticulitis and has an even rarer perforation rate than other locations. 4
• The hepatic flexure is more difficult to assess on physical examination than the cecum, making imaging even more critical for diagnosis. 2, 4
• Ultrasound may be used as an initial imaging modality in younger patients to avoid radiation, but CT with IV contrast remains the gold standard when ultrasound is equivocal or unavailable. 3, 2