What is the treatment for sigmoid diverticulitis with fistula, abscess, and possible bowel obstruction?

Treatment for Sigmoid Diverticulitis with Fistula, Abscess, and Possible Bowel Obstruction

For sigmoid diverticulitis complicated by fistula, abscess, and possible bowel obstruction, surgical intervention with sigmoid resection is required as the definitive treatment to control the source of infection and prevent further complications.

Assessment and Initial Management

• Obtain contrast-enhanced abdominal and pelvic CT scan to confirm diagnosis and assess the extent of complications (abscess size, fistula location, degree of obstruction) 1
• Initiate broad-spectrum intravenous antibiotics immediately while preparing for definitive treatment 2
• For patients with sepsis or septic shock, use one of the following antibiotic regimens:
  • Meropenem 1g q6h by extended infusion
  • Piperacillin/tazobactam 4g/0.5g q6h or 16g/2g by continuous infusion
  • Eravacycline 1mg/kg q12h (especially for patients with beta-lactam allergies) 2

Management of Abscess Component

• For the abscess component:
  • If abscess is large (>4-5cm), percutaneous drainage should be performed in conjunction with antibiotic therapy when technically feasible 2
  • Cultures from percutaneous drainage should guide subsequent antibiotic therapy 2
  • If percutaneous drainage is not feasible, careful clinical monitoring is mandatory while on antibiotic therapy, with a low threshold for surgical intervention if clinical deterioration occurs 2

Surgical Management

• For complicated diverticulitis with fistula formation and possible bowel obstruction, prompt and effective source control surgery is strongly recommended 2
• Surgical options include:
  • In stable patients: Primary resection with anastomosis, with or without a diverting stoma 2
  • In critically ill patients or those with multiple comorbidities: Hartmann's procedure (sigmoid resection with end colostomy) 2
  • In patients with physiological derangement: Damage Control Surgery (emergency laparotomy, source control, and application of open abdomen with vacuum-assisted closure) may be considered 2

Special Considerations for Fistula

• Fistulas (colocutaneous, colovesical, colovaginal, etc.) from diverticulitis require surgical excision of the diseased sigmoid segment along with the fistulous tract 3
• The presence of a fistula indicates chronic inflammation and tissue destruction that will not resolve with antibiotics alone 4, 3
• Complete resection of the diseased sigmoid segment is necessary to prevent recurrence 3

Duration of Antibiotic Therapy

• For patients undergoing source control procedures (drainage or surgery):
  • Continue antibiotics for 4 days in immunocompetent and non-critically ill patients 2
  • Continue antibiotics for up to 7 days in immunocompromised or critically ill patients 2
• Prolonged antibiotic therapy (≥4 days) with ceftriaxone may increase the risk of intra-abdominal Enterococcus faecium, which should be considered when selecting antibiotics 5

Post-Treatment Follow-up

• After resolution of the acute episode, early colonic evaluation (colonoscopy) should be planned within 4-6 weeks to rule out underlying malignancy 2
• This is particularly important in cases with abscess or fistula, as these can occasionally be manifestations of an occult colon cancer 2

Pitfalls and Caveats

• Avoid laparoscopic lavage alone as it has a higher risk of failure to control the source of sepsis in cases with fistula and abscess 2
• Non-operative management is not recommended for diverticulitis with fistula, abscess, and possible bowel obstruction due to high failure rates and risk of septic complications 2
• Delaying surgical intervention in patients with these complications can lead to increased morbidity and mortality 2
• Elective sigmoid resection is the definitive treatment for diverticular disease complicated by fistula formation, even after the acute episode has resolved with conservative measures 2, 6