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Allen KamravaMD · MBA · FACS · FASCRS

Can an anorectal abscess be treated without surgery?

In adults presenting with an anorectal (perianal) abscess, does treatment with antibiotics alone, compared with surgical incision and drainage, achieve comparable rates of abscess resolution, recurrence, and subsequent fistula formation?

Evidence review in plain language · compiled 2026-10-20 · checked 2026-10-20 · next 2026-11-20 · automated review, how it works

What the evidence says

Bottom line

No study has directly tested plain antibiotics, with no procedure at all, against surgical incision and drainage for a typical anorectal abscess.

The closest trial compared needle aspiration (a procedure) plus a week of antibiotics with standard incision and drainage, and the abscess came back far more often after needle aspiration (41% vs 15%). Other evidence comes from small retrospective studies in narrow groups like people with blood cancer or on dialysis, or from case reports where antibiotics alone failed and emergency surgery was needed. None of this directly answers whether antibiotics alone, without any drainage, work as well as surgery for a typical adult.

How well studied

Little evidence

The 14 human studies found measure a related question rather than this one, so they can only be read indirectly.

This question weighs several approaches rather than testing one treatment, so there is no single works-or-doesn't verdict. What can be shown is how well it has been studied.

answer it directly
0answer it directly
studies found
19studies found
randomised trials
3randomised trials
people studied
1,452people studied
years covered
2011–2026years covered

What the research shows

  • Resolution without any procedure

    Small retrospective studies in people with blood cancer or on dialysis found no statistically significant difference between antibiotics-alone and surgery in cure or survival, but the groups were small, specific, and not typical adults with a simple abscess.[1,2,3]

    Too little evidence

  • Need for subsequent surgical drainage

    In the one randomized trial that avoided upfront incision, needle aspiration plus antibiotics led to abscess recurrence in 41% of people, compared with 15% after standard incision and drainage.[1]

    Some evidence

  • Recurrence of abscess

    The same trial found recurrence was much more common with needle aspiration plus antibiotics than with incision and drainage; small studies in cancer and dialysis patients found no significant difference, but were underpowered to detect one.[1,2,3,4]

    Some evidence

  • Development of anal fistula

    No study compared fistula rates between antibiotics-alone treatment and surgery. Available trials only tested adding antibiotics after everyone already had surgical drainage, with conflicting results between trials.[1,2,3]

    Not studied

  • Time to symptom resolution

    One small study of 53 people with blood cancer found conservative (non-surgical) treatment led to significantly shorter recovery time than surgery (p=0.048), but recurrence was numerically higher with conservative treatment (23.6%) than surgery (10.4%), a difference the study says was not statistically significant. This population is too narrow to generalize from.[1]

    Too little evidence

  • Pain scores

    None of the studies here measured or compared pain scores between antibiotics-alone treatment and surgery.

    Not studied

What the studies found

  • In small retrospective studies of people with blood cancer, leukemia, or on chronic dialysis, cure rates were not significantly different between antibiotics alone and surgery. Recurrence rates also did not reach statistical significance, though two of the three studies showed a non-significant trend toward fewer recurrences with surgery (10.4% vs 23.6% in one study; p=0.067 and p=0.082 in the others).[1,2,3]

Important limitations

  • The studies that come closest to an antibiotics-alone-versus-surgery comparison were done in narrow groups — people with blood cancer, people on dialysis — not typical healthy adults with a simple abscess.[1,2,3]
  • The one randomized trial that skipped formal incision still used a procedure, needle aspiration, plus antibiotics afterward. It is not a test of antibiotics used entirely alone.[1]
  • Most of the trials here gave antibiotics as an add-on after everyone had already had surgical drainage, so they cannot say whether antibiotics alone could replace surgery.[1,2,3,4,5]
  • The clearest examples of antibiotics alone failing are single case reports, picked out because they were unusual and severe, not because they show what typically happens.[1,2,3]

What kind of studies

  • Retrospective6 · 32%
  • Narrative review4 · 21%
  • Case series4 · 21%
  • Randomised trial3 · 16%
  • Guideline1 · 5%
  • Prospective cohort1 · 5%

The key studies

  • Wang et al. 2025

    Comparing surgical and conservative treatment approaches for perianal abscess in patients with hematologic malignancies: a comprehensive analysis

    Similar cure rates without surgeryRetrospectiveLow qualityRelated question

    53 people60-day follow-up period

    No significant difference in cure rates between conservative and surgical treatment; recurrence was lower with surgery but the abstract also states this difference was not statistically significant; recovery time was shorter with conservative treatment

    Who was studied
    Adults with hematologic cancers who developed a perianal abscess
    What they received
    Conservative (non-surgical) treatment, including pharmacological therapy
    Compared with
    Surgical drainage/intervention
    Main outcome
    Cure (symptom resolution) and recurrence rates within 60 days
    Quality
    Small retrospective study of a narrow, immunocompromised population with non-randomized group assignment and an internally inconsistent recurrence result.
    Limitations
    Retrospective design, small sample size, population limited to patients with hematologic malignancies (not general adults), and the abstract's own recurrence statistics appear contradictory.

    Taken word for word from the abstract

    • population patients with hematologic malignancies
    • intervention conservative treatment
    • comparator surgical intervention
    • primaryOutcome the cure rates between the two groups showed no significant difference
    • result the cure rates between the two groups showed no significant difference (p > 0.05)
    • result the surgical group demonstrated a significantly lower recurrence rate compared to the conservative group, while there was no statistically significant disparity in recurrence rates (10.4% vs. 23.6%, p > 0.05)
    • result Patients with conservative treatment showed significantly shorter recovery time compared to patients with surgical treatment (p = 0.048)
    • n In total, 53 patients were enrolled in this study
    • followUp During the 60-day follow-up period

    BMC Gastroenterol · PMID 40217138 · Read it on PubMed ↗

  • Tedla et al. 2024

    Complex Tunneling Perirectal Abscess: Intra-abdominal and Extraperitoneal Extension of a Persistent Perirectal Abscess

    Antibiotics alone failed, needed surgery.Case seriesVery low qualityRelated question

    1 people2024

    The abscess did not resolve with antibiotics alone and instead tunneled into the abdomen and extraperitoneal space, requiring emergency surgical drainage and debridement

    Who was studied
    an adult with a perirectal abscess that did not go away with outpatient antibiotics
    What they received
    outpatient antibiotic treatment alone (no surgery) tried first
    Compared with
    later emergency surgical drainage and debridement
    Main outcome
    whether the abscess resolved without needing surgery
    Quality
    This is a single, unusual patient's case report, so it cannot show how often antibiotics alone succeed or fail in general.
    Limitations
    Single case report of a rare, severe complication; selected because it was unusual, so it cannot represent typical outcomes of antibiotic-only treatment.

    Taken word for word from the abstract

    • n a 24-year-old African-American female
    • population following a persistent perirectal abscess that had not resolved following conservative outpatient antibiotic management one week prior
    • intervention conservative outpatient antibiotic management one week prior
    • comparator The patient underwent emergent surgical irrigation, drainage, and debridement of multiple abscess cavities
    • primaryOutcome presenting to the ED with mild fevers, nausea, abdominal distension, and lower abdominal pain following a persistent perirectal abscess that had not resolved
    • result CT imaging demonstrating extraluminal air pockets in multiple intra-abdominal and extraperitoneal compartments. The patient underwent emergent surgical irrigation, drainage, and debridement of multiple abscess cavities extending from the original perirectal abscess.

    Cureus · PMID 38711725 · Read it on PubMed ↗

  • Jwa et al. 2022

    Gluteal and Presacral Abscess Due to Crohn's Disease with Multiple Fistulas

    Antibiotics alone failed, surgery needed.Case seriesVery low qualityRelated question

    1 people2022

    antibiotic treatment alone was not enough; the patient developed fever and the abscess got worse, so surgery was needed to drain it

    Who was studied
    21-year-old man with Crohn's disease who developed gluteal and presacral abscesses with fistulas
    What they received
    antibiotics alone (piperacillin/tazobactam) without surgery
    Compared with
    later treated with surgical incision and drainage
    Main outcome
    resolution of abscess, pain and fever
    Quality
    this is a single case report of one patient with Crohn's disease-related abscess, not a comparative study, so it carries very little weight for general treatment decisions
    Limitations
    single case report, patient population is specific to Crohn's disease with gluteal/presacral/fistulizing abscess rather than typical anorectal/perianal abscess, no control group or comparison

    Taken word for word from the abstract

    • population A 21-year-old male was admitted with right buttock and lower back pain with a duration of 3 months. He had a history of CD in the small intestine diagnosed 10 months previously.
    • intervention Treatment was started with piperacillin/ tazobactam antibiotic
    • comparator Therefore, surgical incision and drainage was performed and 4 Penrose drains were inserted.
    • primaryOutcome Patient's pain and fever were resolved following surgery.
    • result Treatment was started with piperacillin/ tazobactam antibiotic but patient developed a fever and abscess extent was aggravated. Therefore, surgical incision and drainage was performed
    • n A 21-year-old male was admitted

    Korean J Gastroenterol · PMID 36567440 · Read it on PubMed ↗

  • Simsek 2022

    Perianal Infections in Patients With Hematologic Malignancy: The Risk of Fournier's Gangrene Leading to Mortality and Irreversible Organ Damage

    Antibiotics alone failed; all needed surgeryCase seriesVery low qualityRelated question

    4 people2022

    all 4 patients progressed to Fournier's gangrene despite antibiotics and required surgery; 1 died, 1 lost a testicle

    Who was studied
    adult men with blood cancers who developed perianal infection
    What they received
    antibiotics alone as initial treatment
    Compared with
    surgical debridement after antibiotics
    Main outcome
    death and organ damage
    Quality
    this is a tiny retrospective case series of only 4 patients with a different, high-risk population, so it cannot reliably answer whether antibiotics alone work for typical anorectal abscess
    Limitations
    very small sample, retrospective, specific to immunocompromised cancer patients who all progressed to a severe complication, no comparison group of abscess patients treated successfully without surgery

    Taken word for word from the abstract

    • population 4 adults with hematologic malignancy who developed perianal infection progressing to FG
    • intervention A broad-spectrum antibiotic regimen was administered as initial empiric therapy at onset of fever
    • comparator All patients underwent surgical debridement, and diverting ostomy was performed in 3 cases.
    • primaryOutcome The primary outcome was mortality.
    • result FG arose in all cases approximately 8.75 days ± 6.94 (range, 3-17 days) after onset of anal pain. All patients underwent surgical debridement
    • n Four male patients with a mean age of 36.75 years

    Wounds · PMID 34928812 · Read it on PubMed ↗

  • Sørensen et al. 2021

    Needle aspiration treatment vs. incision of acute simple perianal abscess: randomized controlled study

    Needle aspiration plus antibiotics; more recurrence than surgeryRandomised trialModerate qualityRelated question

    98 people52 weeks

    abscess recurred far more often after needle aspiration with antibiotics (41%) than after surgical incision (15%); no significant difference in fistula formation, wound healing, quality of life, or continence

    Who was studied
    adults with an acute simple perianal abscess
    What they received
    needle aspiration of the abscess plus a week of antibiotics (clindamycin) afterward
    Compared with
    standard surgical incision and drainage of the abscess
    Main outcome
    abscess coming back (recurrence) after treatment
    Quality
    it is a multi-center randomized trial with a clear primary outcome, but patients and clinicians could not be blinded to whether they had a needle procedure or an incision, and the sample size (98) is modest for detecting all differences.
    Limitations
    unblinded due to the nature of the procedures; only three centers; needle aspiration group received antibiotics as part of a combined procedure rather than antibiotics used alone without any procedure.

    Taken word for word from the abstract

    • population adults with acute perianal abscess
    • intervention The needle aspiration group received clindamycin for one week postoperatively.
    • comparator conventional surgical incision drainage of acute perianal abscess
    • primaryOutcome The primary outcome was abscess recurrence.
    • result The recurrence rate was 41% in needle aspiration and 15% in incision drainage, with HR of 3.033 (p = 0.014). Fistula formation was 15% without significant difference between the groups. There was no significant difference in wound healing, quality of life, or fecal incontinence scores.
    • n A total of 98 patients were included.

    Int J Colorectal Dis · PMID 33447866 · Read it on PubMed ↗

  • Hsieh et al. 2019

    Epidemiology and outcomes of anal abscess in patients on chronic dialysis: a 14-year retrospective study

    No clear difference; surgery trended betterRetrospectiveLow qualityRelated question

    43 peopleone year

    no statistically significant difference in hospital stay, one-year survival, or recurrence between the antibiotics-only group and the surgery group, though surgery showed a non-significant trend toward better in-hospital survival (p=0.082)

    Who was studied
    adults on chronic dialysis who had a first-time anal abscess
    What they received
    antibiotic treatment alone (no surgery)
    Compared with
    surgical treatment for the abscess
    Main outcome
    in-hospital death, one-year death, and one-year recurrence of the abscess
    Quality
    it is a small (43-patient), retrospective, non-randomized chart review in a very specific dialysis population, so it cannot reliably show whether antibiotics alone work as well as surgery.
    Limitations
    retrospective design, small sample size, no randomization, and the population is restricted to chronic dialysis patients rather than general adults with anorectal abscess

    Taken word for word from the abstract

    • population 43 chronic dialysis patients with first-time anal abscess were enrolled
    • intervention 16 (37.2%) received antibiotic treatment alone
    • comparator 27 (62.7%) received surgical treatment
    • primaryOutcome The endpoints of this study were in-hospital mortality, one-year mortality and one-year recurrence.
    • result there was no significant difference in hospital stay, one-year survival or recurrence rate between the surgical group and nonsurgical group. However, there was a trend toward better in-hospital survival in patients who received surgical treatment (p=0.082).
    • n 43 chronic dialysis patients with first-time anal abscess were enrolled

    Clinics (Sao Paulo) · PMID 30916172 · Read it on PubMed ↗

  • Chen et al. 2013

    Clinical and microbiological characteristics of perianal infections in adult patients with acute leukemia

    No clear proof antibiotics alone workRetrospectiveLow qualityRelated question

    74 people2013

    Patients who had surgery tended to have fewer recurrences than those managed without it, but this difference was not statistically significant

    Who was studied
    Adults with acute leukemia who developed perianal infections
    What they received
    Managing perianal infection without surgery (antibiotics alone)
    Compared with
    Surgical intervention for the perianal infection
    Main outcome
    Recurrence of perianal infection
    Quality
    This is a retrospective single-center chart review in a specific immunocompromised population (leukemia patients), with only a non-significant trend reported, so it carries limited weight for general treatment decisions.
    Limitations
    Retrospective design, single center, specific to leukemia patients where surgery is often avoided due to neutropenia/bleeding risk, and the key finding on surgery vs non-surgery did not reach statistical significance (p=0.067)

    Taken word for word from the abstract

    • population The medical records of 1102 adult patients with acute leukemia at a tertiary medical center in Taiwan between 2001 and 2010 were retrospectively reviewed and analyzed.
    • n The prevalence of perianal infection was 6.7% (74 of 1102) in adult patients with acute leukemia.
    • intervention Twenty-five (34%) of 74 patients received surgical intervention.
    • comparator Acute leukemia patients with surgically managed anal fistulas tended to have fewer recurrences (p = 0.067).
    • primaryOutcome Twenty-three (31%) of the 74 patients had recurrent episodes of perianal infections.
    • result Acute leukemia patients with surgically managed anal fistulas tended to have fewer recurrences (p = 0.067).

    PLoS One · PMID 23577135 · Read it on PubMed ↗

  • Sözener et al. 2011

    Does adjuvant antibiotic treatment after drainage of anorectal abscess prevent development of anal fistulas? A randomized, placebo-controlled, double-blind, multicenter study

    Add-on antibiotics after surgery didn't prevent fistulasRandomised trialModerate qualityRelated question

    183 people1-year follow-up

    Fistula formation was not reduced by antibiotics; in fact more patients on antibiotics developed fistulas (37.3% vs 22.4% with placebo)

    Who was studied
    Adults with anorectal abscess who had surgical drainage
    What they received
    Antibiotic (amoxicillin-clavulanic acid) given for 10 days after surgical drainage
    Compared with
    Placebo given after surgical drainage
    Main outcome
    Development of anal fistula within 1 year after drainage
    Quality
    It is a well-designed randomized, double-blind, multicenter trial, but it only analyzed a per-protocol subset (151 of 183 randomized) and tested antibiotics as an add-on after surgery, not as a stand-alone treatment.
    Limitations
    All patients underwent surgical drainage; the trial tested antibiotics as an adjunct to surgery, not antibiotics alone instead of surgery, so it does not address whether abscesses can be treated without surgery.

    Taken word for word from the abstract

    • population Patients who underwent abscess drainage between September 2005 and January 2008 were evaluated for eligibility.
    • intervention Patients were randomly assigned to receive placebo or amoxicillin-clavulanic acid combination treatment for 10 days after abscess drainage.
    • comparator Patients were randomly assigned to receive placebo or amoxicillin-clavulanic acid combination treatment for 10 days after abscess drainage.
    • primaryOutcome The primary end point was rate of anorectal fistula formation at 1-year follow-up.
    • result Fistula formation occurred in 17 patients (22.4%) in the placebo group and in 28 patients (37.3%) in the antibiotic group (P = .044).
    • n Of 334 patients assessed for eligibility, 183 entered the study (placebo, 92; antibiotics, 91).

    Dis Colon Rectum · PMID 21730779 · Read it on PubMed ↗

What actually helps, on this site

More about the condition:

All 19 studiesEvery study that answered the question, with its design, size and result.
The other 11 studiesEverything else the search returned, including anything retracted.

  • Mersal et al. 2026

    Beyond the Knife: A Contemporary Review of Subcutaneous Abscesses

    Surgery still main treatment; antibiotics only adjunct.Narrative reviewLow qualityRelated question

    size not given2026

    States incision and drainage remains the cornerstone of treatment; antibiotics are discussed only as an adjunct to surgical drainage, with conflicting trial evidence for perianal abscesses and clearer benefit for cutaneous abscesses when combined with drainage

    Who was studied
    Adults with subcutaneous or perianal abscesses treated in surgical/emergency settings
    What they received
    Antibiotics as an addition after incision and drainage, not antibiotics used instead of surgery
    Compared with
    Incision and drainage alone, with or without packing
    Main outcome
    Cure rate, recurrence, and development of fistula-in-ano
    Quality
    This is a narrative review summarizing other trials and guidelines rather than a primary study testing antibiotics alone as a replacement for surgery.
    Limitations
    Narrative (non-systematic) review without described methodology for study selection; does not test antibiotics alone as a stand-alone treatment without drainage; abscesses still universally drained in the scenarios discussed

    Taken word for word from the abstract

    • population Subcutaneous abscesses are among the most common soft-tissue infections encountered in acute surgical and emergency practice.
    • intervention adding a short course of MRSA-active antibiotics to I&D improves short-term cure and reduces new lesions
    • comparator While incision and drainage (I&D) remains the cornerstone of treatment, the best post-I&D strategy remains debated.
    • primaryOutcome whether adjunct antibiotics improve cure rates or prevent recurrence
    • result For perianal abscesses, the goal shifts to preventing fistula-in-ano: here the trials conflict, pooled estimates hint at a modest benefit from antibiotics, and clinical judgment still matters.

    ANZ J Surg · PMID 41420370 · Read it on PubMed ↗

  • Alam et al. 2025

    Does antibiotic therapy for anal abscess reduce the risk of fistula surgery? A retrospective study

    Antibiotics after incision reduced recurrenceRetrospectiveLow qualityRelated question

    109 peopleapproximately 30 months

    All patients still had incision (a form of surgery); among those not needing immediate fistula surgery, lack of post-incision antibiotics was linked to higher recurrence (18% recurrence overall, antibiotics associated with OR 0.44 for recurrence)

    Who was studied
    Adults with a first perianal (anorectal) abscess treated by incision
    What they received
    Antibiotic therapy given after incision of the abscess
    Compared with
    Incision alone, without post-incision antibiotics
    Main outcome
    Rate of patients needing fistula surgery and/or having the abscess come back
    Quality
    This is a small retrospective chart review without randomization, and the authors themselves say multivariate analysis could not be done due to insufficient data.
    Limitations
    Retrospective design, no randomization, no multivariate analysis possible, and all patients underwent incision (surgery) rather than antibiotics alone replacing surgery.

    Taken word for word from the abstract

    • n 109 were included
    • population all patients presenting in 2019 with a first perianal abscess treated by incision under local anesthesia, with or without antibiotic therapy post-incision
    • intervention The role of post-incision antibiotic therapy is also debated.
    • comparator 55 had incision alone
    • primaryOutcome The primary outcome was the rate of patients requiring fistula surgery and/or experiencing abscess recurrence
    • result the administration of antibiotic therapy post-incision was associated with a reduced likelihood of recurrence
    • result absence of antibiotic therapy post-incision as predictive of recurrence with (OR 0.44)

    Clin Res Hepatol Gastroenterol · PMID 41047078 · Read it on PubMed ↗

  • Blondin et al. 2025

    Antibiotic use during the first episode of acute perianal sepsis: a still-open question

    Antibiotics linked to fewer fistulas, not surgery avoidanceRetrospectiveLow qualityRelated question

    276 people1 year

    Fistula formation was less common in patients who received antibiotics (54.0%) than those who did not (75.0%), a difference that remained significant after statistical adjustment

    Who was studied
    Adults with their first episode of acute perianal (anorectal) abscess/sepsis
    What they received
    Antibiotic therapy given alongside standard treatment
    Compared with
    No antibiotic therapy
    Main outcome
    Development of an anal fistula within 1 year
    Quality
    This is a retrospective cohort study without randomization, so patients who got antibiotics may have differed from those who did not in ways that affected outcomes, and the authors themselves say a causal link could not be established.
    Limitations
    Retrospective design with potential confounding; authors state a causal relationship could not be established; does not report whether abscesses were surgically drained or whether surgery for the abscess itself was avoided.

    Taken word for word from the abstract

    • population patients experiencing their first episode of acute perianal sepsis
    • intervention with and without antibiotic therapy
    • comparator with and without antibiotic therapy
    • primaryOutcome compared the incidence of fistula in ano in patients experiencing their first episode of acute perianal sepsis
    • result fistula formation was identified in 65.6% of all patients, 54.0% of those who had received antibiotics, and 75.0% of those who had not (P<0.001)
    • n This study included 276 patients.

    Ann Coloproctol · PMID 39895142 · Read it on PubMed ↗

  • Onafowokan et al. 2021

    A Series of Haemophilus parainfluenzae Surgical Infections and Review of the Literature

    No real evidence on this question.Case seriesVery low qualityRelated question

    34 people2021

    Among 34 patients with Haemophilus parainfluenzae surgical infections, two had perirectal (perianal-area) abscesses, but the abstract does not describe how these two abscesses specifically were treated or whether antibiotics alone worked; separately, three unrelated intra-abdominal infections were successfully treated with drainage plus antibiotics

    Who was studied
    Patients with surgical infections caused by Haemophilus parainfluenzae bacteria, treated at a rural hospital, including two cases of perirectal abscess
    Main outcome
    Types of infections caused by this bacteria and how they were treated
    Quality
    This is a small case series about a rare bacterium causing many different infection types, not a study designed to test antibiotics-alone treatment of anorectal abscess, so it gives almost no usable evidence for this question.
    Limitations
    Focuses on a specific rare pathogen across many infection sites; only two perirectal abscess cases are mentioned with no treatment detail for them specifically; mostly a case series plus literature review, not a comparative study.

    Taken word for word from the abstract

    • n Thirty-four patients (36 isolates) had HPI surgical infections
    • population Haemophilus parainfluenzae isolates were recovered from patients treated at a rural hospital during a two-year period.
    • population two perirectal abscesses
    • primaryOutcome Thirty-four patients (36 isolates) had HPI surgical infections including 28 skin/soft tissue infections, two bone infections, two perirectal abscesses, one infected hemodialysis catheter, and three IAIs
    • result All three IAIs were mixed infections and successfully managed with percutaneous drainage and antibiotic therapy.

    Surg Infect (Larchmt) · PMID 33970041 · Read it on PubMed ↗

  • Arroyo-Martinez et al. 2020

    Urgent care practice in anorectal abscess. Still a pending task

    All patients had surgery; antibiotics' effect unclear.RetrospectiveLow qualityRelated question

    190 people2020

    all patients underwent surgical drainage; antibiotics were used in some cases but showed no clear impact on recurrence, which was instead linked to presence of an associated anal fistula

    Who was studied
    adults treated for anorectal abscess in an emergency department
    What they received
    antibiotic therapy given alongside surgical drainage
    Compared with
    surgical drainage without antibiotics
    Main outcome
    recurrence of the abscess
    Quality
    this is a retrospective single-center review of ED practice patterns among surgically treated patients, not a comparison of antibiotics alone versus surgery.
    Limitations
    retrospective design, single center, all patients underwent surgical drainage so antibiotics-alone was not actually tested as a treatment strategy.

    Taken word for word from the abstract

    • population Patients who underwent surgery for AA between 2016 and 2017 were included in the study.
    • intervention Antibiotic therapy was prescribed in 62.9% of the cases.
    • comparator The most frequent treatment in the emergency department (ED) was simple drainage (75.8%).
    • primaryOutcome The recurrence risk factors were also evaluated.
    • result without clear impact of any of them on the recurrence of the abscess
    • n corresponding to 190 patients

    Cir Cir · PMID 33254180 · Read it on PubMed ↗

  • Yamana 2018

    Japanese Practice Guidelines for Anal Disorders II. Anal fistula

    Surgery remains main treatment; antibiotics only adjunct.GuidelineLow qualityRelated question

    size not given2018

    Guideline states antibiotics should be given only in specific situations (cellulitis, systemic disease, or when drainage fails) and that spontaneous recovery of fistulas is rare except in children, with surgery remaining the principal approach

    Who was studied
    Adults with anal fistula or perianal abscess
    What they received
    Antibiotic therapy
    Compared with
    Incision and drainage or surgery
    Main outcome
    Whether the abscess/fistula resolves without surgery
    Quality
    This is a narrative consensus guideline summarizing expert recommendations and general knowledge, not a controlled study comparing antibiotics alone to surgery.
    Limitations
    No comparative data, no patient outcomes measured, no study population or follow-up described; it is a background/consensus document rather than an empirical trial.

    Taken word for word from the abstract

    • population Anal fistulas usually result from an anal gland infection in the intersphincteric space
    • intervention Antibiotics should be administered in cases of perianal abscess with surrounding cellulitis, or concomitant systemic disease, or those not alleviated by incision and drainage.
    • comparator The site and size of incision and drainage depend upon the abscess type and location.
    • primaryOutcome As spontaneous recovery is rare, except in the case of children, surgery is the principle approach to anal fistulas.
    • result As spontaneous recovery is rare, except in the case of children, surgery is the principle approach to anal fistulas.

    J Anus Rectum Colon · PMID 31559351 · Read it on PubMed ↗

  • Lourtet Hascoet et al. 2018

    Clinical diagnostic and therapeutic aspects of 221 consecutive anorectal Chlamydia trachomatis and Neisseria gonorrhoeae sexually transmitted infections among men who have sex with men

    Many abscess cases still needed surgery.Prospective cohortLow qualityRelated question

    221 people2018

    27 patients (13.9%) developed anal abscesses, and 14 of them (7.2%) underwent surgery for anal fistula

    Who was studied
    Men who have sex with men with anorectal chlamydia or gonorrhea infection (proctitis)
    What they received
    Antibiotic treatment for chlamydia/gonorrhea infection (not specifically for abscess)
    Main outcome
    Rates of anal abscess and fistula, and whether surgery was needed
    Quality
    This was an observational study of sexually transmitted infections where abscess occurrence was an incidental finding, not a designed comparison of antibiotics versus surgery for abscess treatment.
    Limitations
    The study was designed to describe CT/NG infection prevalence and antibiotic resistance in MSM with proctitis, not to compare antibiotic-only versus surgical management of anorectal abscess; abscess/fistula outcomes were a secondary observation in a different population.

    Taken word for word from the abstract

    • n On 441 rectal samples collected, 221 (50.1%) were positive
    • population all MSM consulting for proctitis at proctology Institute-Saint-Joseph's Hospital, Paris, were included
    • intervention the interest of the association of recommended antibiotics excluding quinolones
    • primaryOutcome Anal abscesses were found for 27 (13.9%) patients, and 14 (7.2%) of them underwent surgery for anal fistula.
    • result Anal abscesses were found for 27 (13.9%) patients, and 14 (7.2%) of them underwent surgery for anal fistula.

    Int J Infect Dis · PMID 29608959 · Read it on PubMed ↗

  • López et al. 2018

    Comparative Study of Drainage and Antibiotics versus Drainage Only in the Management of Primary Subcutaneous Abscesses

    No extra benefit from antibiotics after drainage.Randomised trialModerate qualityRelated question

    165 people7 days to full wound healing

    resolution rate was 96% with antibiotics versus 93% with placebo, a difference that was not statistically significant

    Who was studied
    adults with subcutaneous abscesses (including some perianal abscesses) who had the abscess drained
    What they received
    antibiotic agents given after incision and drainage
    Compared with
    placebo given after incision and drainage
    Main outcome
    abscess resolution rate at day 7
    Quality
    it is a randomized trial with a reasonable sample size, but it studied general subcutaneous abscesses (perianal cases being only a minority) and all patients still underwent surgical drainage, so it does not test antibiotics as a stand-alone alternative to surgery for anorectal abscess.
    Limitations
    Mixes different abscess sites (chest, neck, perianal) with uneven distribution between groups; perianal abscesses were not analyzed separately; all patients received drainage so no group avoided surgery.

    Taken word for word from the abstract

    • n One hundred sixty-five patients were included for analysis.
    • population This was a prospective study of patients undergoing incision and drainage (I&D) of a subcutaneous abscess.
    • population Chest and peri-anal abscesses were statistically more frequent in group 2, whereas neck abscesses were more frequent in group 1
    • intervention Patients were randomly assigned either to receive antibiotic agents (group 1) or placebo (group 2) after I&D.
    • comparator or placebo (group 2) after I&D
    • primaryOutcome The primary end point was resolution rate of the abscess at the seventh day.
    • result Resolution rate was 96% in group 1 and 93% in group 2, with no statistical difference between both (p = 0.28).

    Surg Infect (Larchmt) · PMID 29596040 · Read it on PubMed ↗

  • Wright 2016

    Infectious Diseases Perspective of Anorectal Abscess and Fistula-in-ano Disease

    Review says surgery still needed usually.Narrative reviewLow qualityRelated question

    size not given2016

    This is a narrative literature review summarizing prior studies, not a primary comparative trial; it concludes surgery remains the main treatment and antibiotics alone are rarely sufficient, except in select cases with unusual infections or significant comorbidities.

    Who was studied
    Adults with anorectal abscess or fistula-in-ano
    What they received
    Antibiotic therapy (alone or combined with surgery)
    Compared with
    Surgical incision and drainage
    Main outcome
    Healing and recurrence of anorectal abscess/fistula
    Quality
    It is a narrative review synthesizing mixed study types without a systematic quantitative pooling, so it cannot directly test antibiotics-alone versus surgery.
    Limitations
    Narrative review combining heterogeneous sources (case series, retrospective and prospective studies, guidelines) rather than a direct controlled comparison of antibiotics alone versus surgery.

    Taken word for word from the abstract

    • population Anorectal abscess and fistula-in-ano is a rare disease with an exemplary prognosis.
    • intervention The use of antimicrobial therapy in combination with surgical incision and drainage in the treatment of cryptoglandular disease has failed to improved healing times or reduce recurrences or both.
    • comparator Surgical incision and drainage is the main treatment for anorectal abscess and fistula-in-ano
    • primaryOutcome has failed to improved healing times or reduce recurrences or both
    • result Surgical incision and drainage is the main treatment for anorectal abscess and fistula-in-ano, but a select group of patients with unusual infections benefit from tailored prolonged antimicrobial therapy with the overall recurrence rate remaining low.

    Am J Med Sci · PMID 27079352 · Read it on PubMed ↗

  • Ribière et al. 2014

    [Management of intestinal complications in inflammatory bowel diseases]

    Review: drainage plus antibiotics, not antibiotics aloneNarrative reviewVery low qualityRelated question

    size not given2014

    The review states that abdomino-pelvic abscesses larger than 4-5 cm should be drained and treated with antibiotics, and that anoperineal abscesses must be drained by non-tight setons, with medical treatment (antibiotics and anti-TNF) used alongside drainage rather than antibiotics alone

    Who was studied
    Adults with inflammatory bowel disease (Crohn's disease) who develop intestinal or perianal complications
    What they received
    Antibiotic therapy
    Compared with
    Surgical drainage/seton placement
    Main outcome
    Management approach for abdomino-pelvic or anoperineal abscess
    Quality
    This is a narrative review/expert commentary on IBD complication management, not a controlled study testing antibiotics alone against surgery.
    Limitations
    Narrative review focused on IBD-specific complications rather than a comparative study of general anorectal abscess patients; no original data, no defined antibiotics-alone arm, and population is restricted to Crohn's disease/IBD patients rather than general adults with anorectal abscess.

    Taken word for word from the abstract

    • population The evolution of inflammatory bowel disease (IBD) is characterized by the occurrence of gastrointestinal complications.
    • intervention treated with antibiotics
    • comparator Anoperineal abscess must be drained by non-tight setons.
    • primaryOutcome Abdomino-pelvic abscess should be drained if the size is greater than 4-5 cm and treated with antibiotics.
    • result Abdomino-pelvic abscess should be drained if the size is greater than 4-5 cm and treated with antibiotics. If obstructive signs are present after the resolution of the abscess, surgery is usually required.
    • result Anoperineal abscess must be drained by non-tight setons. Medical treatment also involves antibiotics and antiTNF, usually in combotherapy.

    Rev Prat · PMID 25638864 · Read it on PubMed ↗

  • Tonkić et al. 2013

    [Treatment of fistulizing Crohn's disease]

    Review says drain abscess, don't rely on antibioticsNarrative reviewVery low qualityRelated question

    size not given2013

    The abstract states that if a perianal abscess is present it should be drained urgently; antibiotics are described as useful for complex perianal fistulas but most fistulas relapse when antibiotics are stopped, and surgical therapy (seton, fistulotomy) remains part of first-line treatment

    Who was studied
    Adults with fistulizing Crohn's disease, including those with perianal fistulas or abscesses
    What they received
    Antibiotics (metronidazole and ciprofloxacin) for complex perianal disease
    Compared with
    Surgical drainage and other surgical treatments (seton placement, fistulotomy, stoma)
    Main outcome
    Recommended approach to perianal fistula and abscess management
    Quality
    This is a narrative review summarizing consensus and expert recommendations for Crohn's-related perianal disease, not a controlled study testing antibiotics alone against surgery for abscess.
    Limitations
    Narrative review with no original data, no comparative trial design, and focused specifically on Crohn's disease-related fistulas rather than general anorectal abscess in adults; abscess management is mentioned only briefly alongside fistula treatment.

    Taken word for word from the abstract

    • population The treatment of fistulating Crohn's disease should include a combined medical and surgical approach
    • intervention Antibiotics (metronidazole and ciprofloxacine) are useful for treating complex perianal disease
    • comparator in case of a complex perianal disease, seton placement should also be recommended
    • primaryOutcome The presence of a perianal abscess should be ascertained and if present should be drained urgently
    • result The presence of a perianal abscess should be ascertained and if present should be drained urgently.
    • result Antibiotics (metronidazole and ciprofloxacine) are useful for treating complex perianal disease, however, when discontinued, most of the fistulas relapse.

    Acta Med Croatica · PMID 24471302 · Read it on PubMed ↗

How we searchedThe exact query, the date it ran, and what came back — so you can run it yourself.
Searched
PubMed · ClinicalTrials.gov · Crossref on 2026-10-20
The exact search — paste this into PubMed to repeat it
("Anal Canal"[Mesh] OR anorectal[tiab] OR perianal[tiab] OR perirectal[tiab]) AND ("Abscess"[Mesh] OR abscess[tiab]) AND ("Drainage"[Mesh] OR "incision and drainage"[tiab] OR surgical[tiab] OR surgery[tiab]) AND ("Anti-Bacterial Agents"[Mesh] OR antibiotic*[tiab] OR antimicrobial*[tiab])
PubMed expanded that to: ("Anal Canal"[MeSH Terms] OR "anorectal"[Title/Abstract] OR "perianal"[Title/Abstract] OR "perirectal"[Title/Abstract]) AND ("Abscess"[MeSH Terms] OR "Abscess"[Title/Abstract]) AND ("Drainage"[MeSH Terms] OR "incision and drainage"[Title/Abstract] OR "surgical"[Title/Abstract] OR "surgery"[Title/Abstract]) AND ("Anti-Bacterial Agents"[MeSH Terms] OR "antibiotic*"[Title/Abstract] OR "antimicrobial*"[Title/Abstract])
What came back
288 records found · 197 read · 19 answered the question
Included
  • Human, animal or laboratory studies reporting an outcome relevant to the question
Excluded
  • Records about a different condition or intervention
  • Records reporting no outcome
  • Retracted publications, which are listed but excluded from every count
Limits
  • Details were read from abstracts, not full papers, so anything reported only in a paper's methods section is not captured here.
  • Fields were read from abstracts, not full text, so detail reported only in a paper's methods section is not captured.
  • Evidence strength is adapted from the GRADE framework. It is not a GRADE assessment and was not produced by a GRADE panel.

Automated evidence review — PubMed, ClinicalTrials.gov, Crossref. Search strategy, grading rules and the checks that must pass before anything publishes were written by Allen Kamrava, MD, MBA, FACS, FASCRS, colon & rectal surgery, Beverly Hills. The pages themselves are compiled by software running that method and are not read one by one before publication — saying otherwise would be the one claim here that could not be checked.

How we grade evidence →

  1. 288records came back from the search
  2. 197were read
  3. 19actually answered the question
Risks and safetyReported side effects and who should be careful.
  • Case reports describe anorectal or perirectal abscesses treated with antibiotics alone that did not resolve: one tunneled into the abdomen and needed emergency surgery, another worsened with fever and required drainage, and in people with blood cancer, abscesses progressed to a severe flesh-infection (Fournier's gangrene) despite antibiotics, with one death and one loss of a testicle.
  • In the one trial that tried a non-surgical approach (needle aspiration plus antibiotics), the abscess came back much more often than after standard incision and drainage.
Why people askWhat brings people to this question.
  • Fear of pain, a needle, or a scalpel near a sensitive area
  • Hope that a pill is simpler and less invasive than a procedure
  • Embarrassment about an anal exam or surgery
  • Already being prescribed antibiotics for a related infection and hoping it resolves things
  • Difficulty getting quick access to a surgeon or emergency care
Common questionsShort answers, drawn from the same studies.
Can antibiotics alone cure a perianal abscess?
No trial has tested plain antibiotics, with no drainage procedure, against surgery in typical adults. Case reports show antibiotics alone sometimes fail, and the abscess can spread or worsen, eventually needing emergency surgery.
What happens if an anorectal abscess isn't drained?
This hasn't been tested in a trial, but case reports describe abscesses that didn't resolve with antibiotics alone — one tunneled deeper into the body and another worsened with fever, both needing urgent surgical drainage.
Is needle aspiration with antibiotics as good as surgical drainage?
One randomized trial compared needle aspiration plus a week of antibiotics with standard incision and drainage. The abscess came back in 41% of people after needle aspiration, compared with 15% after incision.
Do antibiotics after surgery prevent a fistula from forming?
Trials disagree. One randomized trial found antibiotics after drainage did not reduce fistula formation — slightly more patients on antibiotics developed one. A separate retrospective study found fewer fistulas with antibiotics. Neither tells us about antibiotics instead of surgery.
Should I stop antibiotics and get surgery instead?
This page can't decide that for your specific case — that's a conversation with the clinician treating you. But the evidence here shows antibiotics-alone failures have been reported, so don't ignore worsening pain, fever, or spreading swelling.
What has changedEvery re-check, and whether it changed the answer.

  1. 2026-10-20

    Re-reviewed under a revised method. 4 new studies · 57 no longer retrieved · evidence strength low → very low · conclusion signal of harm → not applicable.

    How certain we are changed. The conclusion changed.

This is information, not advice

This page summarises published research. It cannot tell you what is happening in your own body, and evidence changes. If something is bleeding, painful, or new, it is worth being looked at — that is a different question from the one on this page, and a better one to bring to a consultation.

Contact the office

Automated evidence review — PubMed, ClinicalTrials.gov, Crossref. Search strategy, grading rules and the checks that must pass before anything publishes were written by Allen Kamrava, MD, MBA, FACS, FASCRS, colon & rectal surgery, Beverly Hills. The pages themselves are compiled by software running that method and are not read one by one before publication — saying otherwise would be the one claim here that could not be checked.

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