Floating free-standing anus. A complication of massive anorectal infection.

In a four-year period, 1,020 anorectal infections were treated. Twenty-four patients (2.3 per cent) developed massive tissue necrosis, leaving the anorectum devoid of its anatomic support unilaterally, bilaterally or circumferentially, thus resulting in a "floating or free-standing" anus. The most significant etiologic factors were diabetes and anorectal trauma. All patients had aggressive supportive therapy, appropriate use of antibiotics based on gram stains and confirmed by subsequent cultures, followed by early extensive debridement of all necrotic tissues. Colostomy was not utilized in any of the patients. There were no deaths in this series, and complete wound healing occurred in eight to 12 weeks with only one minor recurrent infection in the follow-up period that averaged 40 months.