Table of contents

Acute diverticulitis



Acute diverticulitis is a disease resulting from acute inflammation and/or micro-perforation of colonic diverticula.
The putative etiology of acute diverticulitis include alterations in colonic structure, colonic motility, microbiome, genetics, immune system, in addition to connective tissue disorders and environmental factors (obesity, smoking, NSAIDs).
The incidence of acute diverticulitis has increased in the past several decades and is estimated at 188 cases per 100,000 person-years in the US.
Disease course
Alterations in gut motility, intraluminal pressure, and the accumulation of inspissated fecal particles in diverticula leads to erosion of the diverticular wall, causing inflammation that can progress to perforation and diffuse peritonitis. The sequelae of diverticula covered by mesentery may cause phlegmons or abscesses, as well as fistulas.
Prognosis and risk of recurrence
Acute diverticulitis has a recurrence rate of 13-23% in patients with uncomplicated disease, and around 40% in patients with complicated disease.


Key sources

The following summarized guidelines for the evaluation and management of acute diverticulitis are prepared by our editorial team based on guidelines from the American College of Radiology (ACR 2023,2022), the Academy of Emergency Medicine and Care (AcEMC/SIFIPAC/SICUT/WSES/ACOI/SICG 2022), the American College of Physicians (ACP 2022), the German Society of General and Visceral Surgery (DGAV/DGVS 2022), the American Society of Colon ...
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Screening and diagnosis

Differential diagnosis
As per DGAV/DGVS 2022 guidelines:
Include diverticulitis in the differential diagnosis of acute abdominal pain, even in younger patients (< 40 years of age).
Include diverticulitis in the differential diagnosis of acute abdominal pain, even if the localization of pain is right-sided or suprapubic.
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Diagnostic investigations

Initial evaluation: as per DGAV/DGVS 2022 guidelines, elicit medical history
and perform a physical examination in patients with suspected diverticulosis.
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  • Diagnostic imaging

  • Poppy seed test

Diagnostic procedures

Colonoscopy: as per DGAV/DGVS 2022 guidelines, consider performing a colonoscopy (probably with a slightly increased risk of perforation) in certain situations (such as an uncharacteristic clinical picture or disease course) in patients with acute diverticulitis, provided covert perforation and abscesses have been ruled out.
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Medical management

Setting of care: as per ACP 2022 guidelines, manage most patients with acute uncomplicated left-sided colonic diverticulitis in an outpatient setting.

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  • Indications for nonoperative management

  • Antibiotic therapy

  • NSAIDs

Inpatient care

Bowel rest: as per JGA 2019 guidelines, advise dietary restriction and bowel rest in patients with acute diverticulitis who display an inflammatory response without abscess formation or bowel perforation.

Nonpharmacologic interventions

Dietary modifications: as per ASCRS 2020 guidelines, advise reduced meat intake to potentially reduce the risk of diverticulitis.

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  • Smoking cessation

  • Physical activity

  • Weight loss

  • Bed rest

Therapeutic procedures

Percutaneous drainage of diverticular abscesses: as per ASCRS 2020 guidelines, perform image-guided percutaneous drainage in stable patients with abscesses > 3 cm in size.

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  • Laparoscopic lavage and drainage

Perioperative care

Postoperative antibiotic therapy: as per WSES 2020 guidelines, consider a 4-day postoperative antibiotic therapy in patients with complicated acute left-sided colonic diverticulitis if source control has been adequate.

Surgical interventions

Emergency colectomy: as per DGAV/DGVS 2022 guidelines, consider performing surgical exploration, possibly with colectomy (dissection at the terminal ileum and in the upper third of the rectum), in the threatening situation of severe active bleeding that cannot be either endoscopically or angiographically located.

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  • Elective colectomy

  • Technical considerations for surgery

Specific circumstances

Patients with complicated diverticulitis, general indications
As per JGA 2019 guidelines:
Consider antibiotic therapy and bowel rest in patients with complicated colonic diverticulitis, localized peritonitis, and an abscess ≤ 3 cm. Consider ultrasound- or CT-guided drainage in patients with an abscess ≥ 5 cm. Individualize treatment based on clinical status, feasibility of drainage, and resource availability in patients with an abscess 3-5 cm.
Perform colectomy when antibiotic therapy and drainage are ineffective.

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  • Patients with complicated diverticulitis (abscess and localized peritonitis)

  • Patients with complicated diverticulitis (fistula)

  • Patients with complicated diverticulitis (stricture)

  • Elderly patients (diagnosis)

  • Elderly patients (diagnostic imaging)

  • Elderly patients (indications for nonoperative management)

  • Elderly patients (antibiotic therapy)

  • Elderly patients (percutaneous drainage of diverticular abscesses)

  • Elderly patients (laparoscopic lavage and drainage)

  • Elderly patients (emergency colectomy)

  • Elderly patients (elective colectomy)

  • Elderly patients (follow-up)

Preventative measures

Aminosalicylates: as per ASCRS 2020 guidelines, do not offer mesalamine for reducing the risk of diverticulitis recurrence, but consider for reducing chronic symptoms.

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  • Rifaximin

  • Probiotics

  • Secondary prevention

Follow-up and surveillance

Follow-up: as per ESCP 2020 guidelines, avoid obtaining endoscopic follow-up in patients with symptom-free recovery after a single episode of CT-verified uncomplicated diverticulitis. Follow-up all other patients treated without resection for acute diverticulitis with an examination of the colon at least 6 weeks after the acute episode, if not done within the last 3 years.

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  • Management of recurrent diverticulitis