Anal Fistula
Understanding anal fistula through community experiences and medical research.
Community experiences, not medical advice
Understanding anal fistula through community experiences and medical research.
An anal fistula is a small tunnel between the end of the bowel (the anal canal) and the skin near the anus. It usually follows an anal abscess that drains and leaves a channel behind. You can read the NHS overview on the NHS website.
This is a different condition from an anal fissure (a tear in the lining of the anal canal). The names sound alike and people often mix them up, but the anatomy, the usual story after an abscess, and the treatments are not the same.
Most cryptoglandular fistulas do not heal on their own. The NHS notes that surgery is recommended in most cases. Mapping the tract — often with MRI or endoanal ultrasound — helps the surgical team choose an approach that balances healing against sphincter risk. Complex perianal fistulas in Crohn's disease follow a different care path; see our IBD page for that overlap.
Clinicians usually start with the history (often a previous abscess that drained, then ongoing discharge or a small opening near the anus) and a careful examination. Imaging is used to map the tract before surgery: MRI and endoanal ultrasound are the tools NHS and ACPGBI guidance describe for understanding how the fistula relates to the sphincter muscles.
It is not something a webpage can confirm. Bleeding, pain, or a lump near the anus can also be haemorrhoids (piles) or a fissure — a clinician needs to look before you settle on a label. If there is known or suspected Crohn's disease, the work-up and treatment plan change; that pathway is covered under IBD rather than here.
These are options clinicians, guidelines, and community members discuss around anal fistula — not a self-treatment plan.
These are cautions, not approaches people discuss:
The Association of Coloproctology of Great Britain and Ireland second Position Statement on anal fistula. It covers classification, imaging, setons, fistulotomy, flaps, and sphincter-preserving options, including how Crohn's-related fistulas differ.
View position statementNHS overview of anal fistula, including the usual link to abscess, why surgery is often needed, and how imaging helps plan treatment.
Visit ResourceNICE guidance on bioprosthetic plug insertion as a sphincter-preserving option reviewed for anal fistula; evidence varies by fistula type.
View guidanceNICE guidance on endoscopic ablation as a sphincter-preserving option reviewed for selected fistulas; evidence varies by fistula type.
View guidanceNICE guidance on radially emitting laser fibre treatment for anal fistula; evidence varies by fistula type.
View guidanceNICE technology appraisal of darvadstrocel for previously treated complex perianal fistulas in Crohn's disease. It confirms these fistulas sit on a distinct Crohn's pathway, separate from cryptoglandular fistula surgery.
View appraisal