Antibiotics After Incision and Drainage to Prevent Fistula Formation After First Episode of Perianal Abscess

The goal of this clinical trial is to learn if antibiotics can prevent the formation of fistula-in-ano after incision and drainage of a first time of perianal abscess in adults. A perianal abscess is a collection of infected fluid near the anus. A Fistula-in-ano is an abnormal tunnel that can form between the anal canal and the skin after an abscess. The main questions it aims to answer are: Does taking antibiotics after incision and drainage of a perianal abscess lower the chance of developing a Fistula-in-ano? What medical problems or side effects do participants have after taking antibiotics or not taking antibiotics? Researchers will compare participants who recieve antibiotics after abscess drainage with paticipants who do not recieve antibiotics after abscess drainage, to see if antibiotics lower the chance of developing a Fistula-in-ano. Participants will: Be randomly assigned to recieve antibiotics for 7 days after abscess incision and drainage or to not recieve antibiotics after abscess incision and drainage. Attend follow-up clinic visits after incision and drainage as part of their standard of care. Complete follow-up phone call about 12 months after incision and drainage. Allow the study team to review their medical record for abscess treatment, symptoms, recurrence, fistula-in-ano formation, additional procedures, and antibiotics side effects.

Inclusion Criteria: * Age 18 years or older * First episode of perianal abscess requiring incision and drainage * Able to provide informed consent * English or Spanish speaking patient * Treating surgical team has determined that incision and drainage is clinically indicated as part of standard care Exclusion Criteria: * Known fistula-in-ano at presentation * Prior perianal abscess within 12 months * History of inflammatory bowel disease, including Crohn's disease or ulcerative colitis * Known or suspected anorectal malignancy * Necrotizing soft tissue infection or Fournier's gangrene * Systemic infection or sepsis * Significant surrounding cellulitis or extensive soft-tissue infection for which antibiotics are clinically indicated * Immunocompromised or immunosuppressed status, including active chemotherapy or radiation therapy, history of transplant, chronic systemic steroids, biologic immunosuppressive therapy, advanced or uncontrolled HIV/AIDS, or other clinically significant immunosuppression * Cardiac condition requiring antibiotic prophylaxis or antibiotic therapy for procedures involving infected tissue * Need for non-study antibiotics at the time of enrollment for another infection or medical indication * Contraindication, allergy, or intolerance to all study antibiotic regimens * Pregnant * Prisoner * Minor * Adult unable to provide informed consent