FISTULA‐IN‐ANO: A PROSPECTIVE STUDY OF 107 PATIENTS

Abstract

The presence of additional anatomic complexity should always be anticipated in trans-sphincteric fistulas. Trans-sphincteric and 'high' fistulas are more likely to occur in females, and in patients with previous perianal sepsis or surgery for fistula. External openings close to the posterior midline almost always underlie simple fistulas, whereas posterolateral external openings are predictive of complex fistulas.