Can diverticulitis cause recurrent pelvic abscesses in an adult over 50 years old with left‑sided colonic diverticulosis?

Can Diverticulitis Cause Recurrent Pelvic Abscesses?

Yes, diverticulitis can absolutely cause recurrent pelvic abscesses, particularly in adults over 50 with left-sided colonic diverticulosis, and this represents complicated diverticulitis requiring aggressive management and consideration for surgical intervention.

Understanding the Mechanism

Left-sided sigmoid diverticulitis can lead to pelvic abscess formation through perforation of inflamed diverticula, with the abscess tracking into the pelvis due to anatomic proximity 1. Complicated diverticulitis is defined as inflammation associated with abscess, phlegmon, fistula, obstruction, bleeding, or perforation, occurring in approximately 12% of acute diverticulitis cases 1. The sigmoid colon's location adjacent to pelvic structures makes pelvic abscess a common manifestation of complicated disease 1.

Risk of Recurrence After Initial Abscess

The recurrence rate after medically treated diverticular abscess is alarmingly high—ranging from 20% to 60.5% in published series 2, 3, 4. This is substantially higher than the 8-36% recurrence rate seen with uncomplicated diverticulitis 1.

Key Evidence on Recurrence Patterns:

• A large tertiary center study of 185 patients with diverticular abscess showed 60.5% developed recurrent diverticulitis after initial successful nonoperative management, with a median time to recurrence of 5.3 months 3
• Of those with recurrence, 45.6% had progression to a higher Hinchey stage compared to their index presentation, and 63% developed local disease complications including recurrent abscess, fistula, stricture, or peritonitis 3
• Another series reported 20% overall recurrence after diverticular abscess, with rates of 30% after antibiotics alone, 27% after percutaneous drainage plus antibiotics, and only 5% after surgical resection 4

Clinical Presentation in Older Adults

Elderly patients (>50-65 years) present with atypical features that can delay diagnosis: only 50% have left lower quadrant pain, 17% have fever, and 43% lack leukocytosis 1. This diagnostic challenge increases the risk of progression to complicated disease with abscess formation 1.

Management Algorithm for Recurrent Pelvic Abscess

Initial Episode with Pelvic Abscess:

1. Imaging confirmation: CT abdomen/pelvis with IV contrast is mandatory to confirm abscess size, location, and rule out free perforation 1, 5

2. Treatment based on abscess size:

• Abscess <4-5 cm: IV antibiotics alone for 7 days (ceftriaxone plus metronidazole OR piperacillin-tazobactam) 1, 6
• Abscess ≥4-5 cm: CT-guided percutaneous drainage PLUS IV antibiotics, continuing antibiotics for 4 days after adequate source control in immunocompetent patients 1, 6
• Generalized peritonitis or sepsis: Emergent surgical consultation for source control (Hartmann procedure or primary resection with anastomosis) 1, 6

For Recurrent Pelvic Abscess:

The occurrence of a second pelvic abscess fundamentally changes management priorities 3, 4.

Immediate actions:

• Obtain urgent repeat CT imaging to assess abscess size, complexity, and exclude fistula formation 1, 5
• Initiate broad-spectrum IV antibiotics immediately 1
• Arrange urgent surgical consultation—do not delay 1

Definitive management: Elective sigmoidectomy should be strongly recommended after resolution of the acute episode 1. The 2022 ACP guidelines suggest discussing elective surgery for patients with complicated diverticulitis, as recurrence after abscess carries a 21.5% absolute risk reduction with surgery compared to continued conservative management 1.

Why Percutaneous Drainage Alone Is Insufficient

CT-guided drainage of diverticular abscess does not lower future recurrence or complication rates and frequently serves only as a bridge to surgery 3. In one series, 73.8% of patients who had successful CT-guided drainage experienced recurrence, with 71.1% of those recurrences involving local complications 3. Larger abscesses (mean 5.3 cm vs 3.2 cm) are associated with significantly higher recurrence risk 3.

Special Considerations in Older Adults

Age >65 years requires a lower threshold for antibiotic therapy even with localized complicated diverticulitis 1. Comorbidities—not age alone—drive mortality risk, but elderly patients have higher in-hospital mortality (9.7% for ages 65-79,17.8% for >80 years) and postoperative mortality after emergency surgery 1.

Critical Pitfalls to Avoid

• Do not assume successful drainage of the first abscess eliminates recurrence risk—the underlying diverticular disease persists and 60% will have another episode 3, 4
• Do not delay surgical referral after a second abscess—recurrent complicated diverticulitis warrants elective resection discussion 1
• Do not miss fistula formation—colovesical, colovaginal, and colocutaneous fistulas are among the most frequent complications of recurrent diverticular abscess 3
• In young women, do not misdiagnose diverticular pelvic abscess as tuboovarian abscess—the sigmoid colon's proximity to the left ovary can lead to perforation into the ovary, and failure to treat underlying diverticulitis leads to persistent or recurrent pelvic infection 7

Post-Acute Follow-Up

Colonoscopy is mandatory 4-6 weeks after resolution of complicated diverticulitis to exclude colorectal malignancy, which has a 7.9% prevalence in patients with complicated disease 1, 5.