fistula

An anal fistula (also called fistula-in-ano) is an abnormal tunnel that forms between the anal canal (inside the anus) and the skin near the anus. It’s usually the result of a previous or ongoing anal abscess that didn’t heal properly. 🔍 What Causes an Anal Fistula? Chronic anal abscesses (most common) Blocked anal glands Inflammatory bowel disease (especially Crohn’s disease) Tuberculosis or HIV (in rare cases) Trauma, radiation, or surgery ✅ Symptoms Persistent or recurrent pus or discharge near the anus Pain, especially when sitting, walking, or during bowel movements Swelling or a lump near the anus Bleeding Irritation or redness around the opening Fever or chills (if infection is present) ⚠️ If an abscess reappears or continues to drain, a fistula is likely present. 📌 Types of Fistulas (Parks Classification) Type Description Intersphincteric Between internal and external sphincters (most common) Transsphincteric Passes through both sphincters Suprasphincteric Extends above external sphincter Extrasphincteric Outside the sphincter muscles (rare and complex) 🧪 Diagnosis Physical exam (look for external opening near anus) Digital rectal exam Probing of the tract (by a doctor) MRI or endoanal ultrasound (for complex fistulas) Fistulogram (X-ray with dye – rarely used now) 💊 Treatment ❗ Fistulas do not heal on their own — surgical treatment is usually required. 🔧 Surgical Options Procedure Description Used for Fistulotomy Open the fistula tract to allow healing Simple, low fistulas Seton placement Thread placed in tract to drain and slowly cut through muscle Complex or high-risk fistulas LIFT procedure Ligation of the fistula tract at its origin Deep, transsphincteric fistulas Fibrin glue / plug Minimally invasive, fills the fistula tract Low success rate, used selectively Advancement flap Covers internal opening with a flap of rectal tissue Complex or recurrent cases VAAFT / laser ablation Minimally invasive options For selected patients