About this condition
An anal fistula is an abnormal tract connecting the anal canal or rectum with skin near the anus. It often develops after an abscess and may produce recurring discharge or inflammation.
What you should know
The external opening can be very small, and symptoms may settle and then return. A skin opening that closes for a while does not prove the underlying tract has disappeared. Some fistulas cross important parts of the anal sphincter, which affects the safest approach.
Symptoms and reasons for assessment
Pus or foul-smelling fluid, skin irritation, damp clothing, soreness during bowel movements and repeated swelling are possible. A new abscess may produce sudden pain, fever, chills or spreading redness.
Other possible explanations
Similar discharge can occur with perianal abscesses, inflamed skin, cysts or bowel conditions such as Crohn disease. The course of the tract and any relation to the sphincter must be understood before a procedure is selected.
How the problem is assessed
The clinician asks about previous abscesses, recurrent episodes and bowel symptoms, then examines the perianal area for openings and scars. MRI or another assessment may be considered for complex, recurrent or deep tracts. The management plan depends on anatomy and continence risk.
Treatment and follow-up options
Most established anal fistulas do not reliably heal with topical products alone. Surgical options can be discussed with a colorectal specialist, but the chosen technique must balance healing against injury to the anal sphincter and the risk of affecting bowel control. Do not assume every fistula can be simply cut open.
When urgent care is needed
Fever, increasing pain, significant swelling, chills or pronounced weakness may indicate a new abscess and require urgent assessment. Recurrent discharge without fever still merits a scheduled specialist review. For a life-threatening condition, call 103.
Related health information
Paraproctitis (perianal abscess); Discharge from the anus; Proctologist consultation.
Signs and symptoms
Diagnosis and tests
Care and treatment approaches
When to seek urgent care
Frequently asked questions
Can an anal fistula close permanently by itself?
Often it does not. A specialist should assess the tract and discuss the treatment options.
Is a fistula always visible on the skin?
No. The opening can be tiny, and deep or complex tracts may need additional assessment.
Why does the anal sphincter matter during treatment?
Some procedures can affect bowel control if sphincter muscles are injured, so anatomy and risks must be considered.
Information sources
Medical source links used when preparing this article.
Important information
A medical consultation is needed for diagnosis and treatment recommendations.
Self-treatment can be harmful to your health.
