From the Guidelines
Anal abscesses require prompt surgical drainage, and the primary treatment involves incision and drainage performed by a surgeon or emergency physician, as recommended by the most recent guidelines 1.
Key Considerations
- The procedure is typically done under local anesthesia, where a small incision is made to allow the pus to drain.
- Following drainage, patients should take sitz baths (sitting in warm water) 2-3 times daily for 10-15 minutes to keep the area clean and promote healing.
- Pain management usually includes acetaminophen (500-1000mg every 6 hours) or ibuprofen (400-600mg every 6-8 hours) as needed.
- Antibiotics are not routinely required after drainage unless there are signs of spreading infection, diabetes, or immunosuppression, as suggested by recent guidelines 1.
Special Considerations
- In patients with anorectal abscess and an obvious fistula, a fistulotomy at the time of abscess drainage may be performed only in cases of low fistula not involving sphincter muscle (i.e., subcutaneous fistula) 1.
- In patients with anorectal abscess and an obvious fistula involving any sphincter muscle, a loose draining seton may be placed 1.
- The role of wound packing after anorectal abscess drainage remains unproven, and its use should be left to individual unit policy and patient discussion 1.
Prevention and Complications
- Approximately 30-50% of anal abscesses can develop into anal fistulas (abnormal connections between the anal canal and skin), which may require additional surgical treatment.
- Anal abscesses form when the glands in the anal canal become blocked and infected, often with bacteria from the gastrointestinal tract.
- Maintaining good hygiene, avoiding constipation, and seeking prompt medical care for rectal pain can help prevent complications.
From the Research
Treatment of Anal Abscess
- The golden standard of acute treatment is incision and drainage 2
- Knowledge of the anatomy of the anal area and the abscess involvement of perianal spaces is crucial in order to perform safe and correct surgical treatment 2
- Pre- and perioperative imaging with magnetic resonance imaging, endoanal ultrasonography or CT facilitates correct incision and drainage 2
- Antibiotics as conservative approach have no place in the treatment of abscesses 2
Fistulotomy in the Treatment of Anal Abscesses
- Primary fistulotomy at the time of abscess drainage is safe and efficient 3
- The recurrence rate after surgery was significantly higher in the group treated by drainage alone (88%) compared to the group treated by drainage and fistulotomy (4.8%) 3
- There was a tendency to a higher risk of fecal incontinence in the fistulotomy group (5% vs 1%), although this difference was not significant 3
Use of Antibiotics in the Prevention of Anal Fistulas
- Antibiotic therapy following incision and drainage of anorectal abscesses is associated with a 36% lower odds of fistula formation 4
- A systematic review and meta-analysis of six studies with 817 patients found that fistula rate in subjects receiving antibiotics was 16% versus 24% in those not receiving postoperative antibiotics 4
- A multicentre, double-blind, randomised, placebo-controlled trial is investigating whether addition of antibiotics to surgical drainage of perianal abscess results in a reduction in perianal fistulas 5
Incision and Drainage with or without Treatment of Anal Fistula
- Treating the fistula at the same time as incision and drainage of the abscess may reduce the likelihood of recurrent abscess and the need for repeat surgery 6
- Meta-analysis showed a significant reduction in recurrence, persistent abscess/fistula or repeat surgery in favour of fistula surgery at the time of abscess incision and drainage 6
- Incontinence at one year following drainage with fistula surgery was not statistically significant 6