Guideline sources The following summarized guidelines for the evaluation and management of anorectal abscess are prepared by our editorial team based on guidelines from the American Society of Colon and Rectal Surgeons (ASCRS 2022; 2020), the World Society of Emergency Surgery (WSES/AAST 2021), the American College of Radiology (ACR 2021), the American College of Gastroenterology (ACG 2018), and the Association of Coloproctologists in Germany (BCD/DGAV/DGAV/DDG/DGGG/DGU/DGK/AGUB/CACP 2017). 1 2 3 4 5 6 7 Guidelines 1. Diagnostic investigations Clinical examination: As per ASCRS 2022 guidelines, elicit a disease-specific history and perform a physical examination assessing symptoms, relevant history, location of the abscess and fistula, and the presence of secondary cellulitis in the initial evaluation of patients with anorectal abscess. B As per WSES 2021 guidelines, consider eliciting a focused medical history and perform a complete physical examination, including a DRE, in patients with suspected anorectal abscess. C https://web.pathway.md/diseases/recMcRK6cN06YZbXf 1/4 6/23/23, 2:37 AM Anorectal abscess Pathway As per DGAV 2017 guidelines, elicit a medical history and perform a clinical examination to establish the indication for surgery in patients with anorectal abscess. A Laboratory tests: Consider obtaining the following tests to identify an undetected diabetes mellitus in patients with suspected anorectal abscess: serum glucose hgb A1c urine ketones. B Consider obtaining the following tests to assess the status of patients with suspected anorectal abscess and signs of systemic infection or sepsis: CBC serum creatinine inflammatory markers (such as CRP, procalcitonin, and lactate). C Diagnostic imaging: As per ASCRS 2022 guidelines: Do not obtain routine diagnostic imaging in patients with anorectal abscess. D Consider obtaining imaging in selected patients with occult anorectal abscess, immunosuppression, or anorectal Crohn's disease. B As per WSES 2021 guidelines, consider obtaining imaging investigations (MRI, CT, or anorectal ultrasound depending on the specific clinical scenario and the available skills and resources) in patients with suspected anorectal abscess in case of atypical presentation or suspicion of occult supralevator abscesses, complex anal fistula, or perianal Crohn's disease. C As per ACR 2021 guidelines, consider obtaining pelvic MRI without and with IV contrast or pelvic CT with IV contrast as the initial imaging in patients with suspected anorectal abscess. C As per ACG 2018 guidelines, consider obtaining cross-sectional imaging with MRI of the pelvis and/or EUS to characterize perianal involvement and perirectal abscesses in patients with Crohn's disease. E As per DGAV 2017 guidelines, obtain further investigations (anorectal ultrasound, MRI) only in case of recurrent, complex abscesses and complex fistulas of difficult clinical classification. A 2. Medical management Antibiotic therapy: As per ASCRS 2022 guidelines, reserve antibiotics for patients with anorectal abscess complicated by cellulitis, systemic signs of infection, or underlying immunosuppression. B As per WSES 2021 guidelines, consider administering antibiotics in patients with drained anorectal abscess in the presence of sepsis and/or surrounding soft tissue infection or in case of disturbances of the immune response. C https://web.pathway.md/diseases/recMcRK6cN06YZbXf 2/4 6/23/23, 2:37 AM Anorectal abscess Pathway 3. Surgical interventions Incision and drainage: As per ASCRS 2022 guidelines, perform prompt incision and drainage in patients with acute anorectal abscess. B As per WSES 2021 guidelines, perform incision and drainage in patients with anorectal abscess. B Show 4 more As per DGAV 2017 guidelines, perform surgery, via a transrectal or perianal approach depending on the location of the abscess, aiming for thorough drainage of the infection focus while preserving the sphincter structures in patients with anorectal abscess. E Show 2 more Concomitant fistulotomy: As per ASCRS 2022 guidelines, consider performing concomitant fistulotomy along with abscess drainage in selected patients with simple anal fistula. C As per WSES 2021 guidelines, consider performing fistulotomy at the time of abscess drainage in patients with anorectal abscess and an obvious fistula, only in cases of low fistula not involving sphincter muscle (subcutaneous fistula). C Show 2 more 4. Specific circumstances Patients with Crohn's disease: As per WSES 2021 guidelines, perform adequate surgical drainage of a perianal abscess without searching for an associated fistula in patients with Crohn's disease. B Show 3 more As per ASCRS 2020 guidelines, consider administering antibiotics with or without drainage in patients with penetrating Crohn's disease with abscess formation, followed by interval elective resection or medical therapy depending on the clinical situation and patient preferences. C As per ACG 2018 guidelines, perform prompt surgical drainage of the perianal abscess in patients with Crohn's disease. E Perform abscess drainage, surgically or percutaneously, before treatment of fistulizing Crohn's disease with anti-TNF agents. B References 1. Andreas Ommer, Alexander Herold, Eugen Berg et al. German S3 guidelines: anal abscess and fistula (second revised version). Langenbecks Arch Surg. 2017 Mar;402 2 191 201. Open 2. Antonio Tarasconi, Gennaro Perrone, Justin Davies et al. Anorectal emergencies: WSES AAST guidelines. World J Emerg Surg. 2021 Sep 16;16 1 48. Open https://web.pathway.md/diseases/recMcRK6cN06YZbXf 3/4 6/23/23, 2:37 AM Anorectal abscess Pathway 3. Lichtenstein GR, Loftus EV, Isaacs KL et al. ACG Clinical Guideline: Management of Crohn's Disease in Adults. Am J Gastroenterol. 2018 Apr;113 4 481 517. Open 4. Wolfgang B Gaertner, Pamela L Burgess, Jennifer S Davids et al. The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Anorectal Abscess, Fistula-in-Ano, and Rectovaginal Fistula. Dis Colon Rectum. 2022 Aug 1;65 8 964 985. Open 5. Amy L Lightner, Jon D Vogel, Joseph C Carmichael et al. The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Surgical Management of Crohn's Disease. Dis Colon Rectum. 2020 Aug;63 8 1028 1052. Open 6. Belinda De Simone, Justin Davies, Elie Chouillard et al. WSES AAST guidelines: management of inflammatory bowel disease in the emergency setting. World J Emerg Surg. 2021; 16 23. Open 7. Expert Panel on Gastrointestinal Imaging: Angela D. Levy, MD, Peter S. Liu et al. ACR Appropriateness Criteria Anorectal Disease. ACR. 2021. Open 8. Vogel JD, Johnson EK, Morris AM et al. Clinical Practice Guideline for the Management of Anorectal Abscess, Fistula-in-Ano, and Rectovaginal Fistula. Dis Colon Rectum. 2016 Dec;59 12 1117 1133. Open https://web.pathway.md/diseases/recMcRK6cN06YZbXf 4/4