Retrospective Clinical and Microbiologic Analysis of Patients with Anorectal Abscess

Background: We conducted a clinical and microbiologic analysis of patients presenting with anorectal abscess. Methods: A total of 505 adult patients presenting from January 2011 to December 2017 were analyzed retrospectively. Microbiologic data were available for 211 patients. Results: The mean age at presentation was 39.5 (standard deviation 12.4) years, and 81.4% of the cohort were men. One hundred fifteen patients (22.8%) had diabetes mellitus, and 15 patients (3.0%) had inflammatory bowel disease. There were 184 patients (36.4%) who required admission for more than 24 hours with a median length of stay of two days (interquartile range 2, 4) days. The most common microorganism was Escherichia coli (37.6%), followed by Bacteroides spp. (13.2%) and Streptococcus spp. (13.2%). Escherichia coli accounted for 34.9% of the microorganisms cultured from patients with diabetes mellitus followed by Streptococcus spp. (27%) and Klebsiella pneumoniae (20.6%). Conclusions:Escherichia coli is the most common micro-organism cultured from patients presenting with anorectal abscess. Despite an increase in community-acquired multi-resistant strains, our results show a low overall incidence of such isolate. Our study provides a large microbiologic sample of patients with anorectal abscess to expand the present knowledge of the etiology of a common surgical condition.