New ACG guideline outlines outpatient management of diverticulitis

Clinical takeaway: Most patients with acute uncomplicated diverticulitis do not require routine antibiotics. Management should emphasize CT-confirmed diagnosis, selective use of antibiotics and colonoscopy, counseling on evidence-based lifestyle measures to reduce recurrence, and individualized decisions about elective surgery.

The American College of Gastroenterology (ACG) has released its first dedicated clinical guideline for outpatient management of colonic diverticulitis, reflecting current evidence on diagnosis, treatment, recurrence prevention, and patient counseling. The guideline emphasizes that diverticulitis is a heterogeneous disease and that consultations should focus on diagnostic accuracy, the expected clinical course, recurrence risk, appropriate antibiotic use, and preventive strategies.

A key recommendation is that routine antibiotic therapy is no longer advised for low-risk patients with acute uncomplicated diverticulitis. Instead, antibiotics should be reserved for patients with high-risk features, immunocompromise, frailty, prolonged symptoms, systemic inflammatory findings, or when safe outpatient management cannot be ensured. When antibiotics are indicated for outpatient treatment, recommended regimens include amoxicillin-clavulanate or combination therapy with metronidazole plus trimethoprim-sulfamethoxazole, ciprofloxacin, or levofloxacin, typically for 4 to 7 days. Amoxicillin-clavulanate may help avoid fluoroquinolone-associated adverse effects while providing similar efficacy.

The guideline also recommends CT imaging to confirm suspected diverticulitis, particularly at the initial presentation or in severe disease. Following recovery, colonoscopy is recommended after complicated diverticulitis to exclude missed colorectal cancer. After uncomplicated diverticulitis, colonoscopy is suggested only for patients with alarm symptoms or those who are not current with colorectal cancer screening.

To reduce recurrence risk, the guideline encourages a healthy dietary pattern rich in fruits, vegetables, whole grains, and legumes while limiting red meat, processed grains, trans fats, and sweets. Patients should not be advised to avoid nuts, seeds, corn, or popcorn. Additional recommendations include regular physical activity, maintaining a healthy weight, smoking cessation, moderation of heavy alcohol use, and minimizing NSAID use when clinically appropriate.

For patients with recurrent uncomplicated diverticulitis, elective colectomy should no longer be based solely on the number of previous episodes. Instead, referral for surgical consultation should be individualized for patients whose recurrent disease significantly impairs quality of life. The guideline also recommends against using probiotics, mesalamine, or rifaximin to prevent recurrent diverticulitis because evidence does not demonstrate meaningful benefit.

"Clinicians should integrate patient comorbidities, overall health, and preferences to ensure patient-centered care," the guideline authors wrote.

Source: Peery AF, et al. (2026 Jul) Am J Gastroenterol. ACG Clinical Guideline: Colonic Diverticulitis