Diverticulitis is a common reason for presentation to the Emergency Department (ED). However, as imaging options, risk stratification tools, and antibiotic options have expanded, there is a need for current data on the changes in incidence, computed tomography (CT) performance, antibiotic usage, and disposition over time.

This was a cross-sectional study of ED patients with a diagnosis of diverticulitis from 1/1/2016 to 12/31/2023. Using the Epic Cosmos database, all ED visits for acute diverticulitis were identified using ICD-10 codes. Outcomes included total ED presentations for diverticulitis, admission rates, CTs performed, outpatient antibiotic prescriptions, and antibiotics administered in the ED for admitted patients.

There were 186,138,130 total ED encounters, with diverticulitis representing 927,326 (0.50 %). The rate of diverticulitis diagnosis increased from 0.40 % to 0.56 % over time. The admission rate declined over time from 33.6 % to 27.7 %, while the CT rate rose from 83.0 % to 92.6 %. Among those discharged, 90.4 % received an antibiotic, which remained consistent over time. Metronidazole (55.1 %) and ciprofloxacin (40.8 %) were the most commonly prescribed antibiotics, followed by amoxicillin-clavulanate (36.1 %). Among those admitted, most received either metronidazole (62.0 %), a fluoroquinolone (40.4 %), a third-generation cephalosporin (18.9 %), or a penicillin-based agent (38.1 %). Among both discharged and admitted patients, there was a marked shift to penicillin-based agents as the primary antibiotic regimen.

Diverticulitis remains a common ED presentation, with a gradually rising incidence over time. Admission rates have decreased, while CT imaging has become more common. Most patients receive antibiotics, though the specific antibiotic has shifted in favor of penicillin-based agents. These findings can provide key benchmarking data and inform future initiatives to guide imaging and antibiotic use.