Anal Fistula Surgery: Seton Removal & Laying Open Procedure

Dr. Ilango Sethu

Surgical Gastroenterology · Iswarya Hospital

Anal fistulas rarely heal without surgery. Learn about the two most common procedures — seton placement and fistulotomy (laying open) — and what to expect.

An anal fistula is an abnormal tunnel connecting the inside of the anal canal to the skin around the anus. Most fistulas develop after an anal abscess and require surgery to heal permanently.

What Is a Seton?

A seton is a thread or suture material that is passed through the fistula track. It works by:

Cutting seton: Gradually tightening over weeks to divide the sphincter slowly, preserving continence

Draining seton: Keeps the fistula open and draining while allowing tissue to build up before definitive surgery

The seton is tightened (or replaced) at regular intervals during clinic visits until it cuts through the muscle slowly.

Laying Open (Fistulotomy)

Fistulotomy is the most common surgery for simple, low fistulas. The surgeon:

1. Opens the entire fistula track from inside out

2. The wound heals by "secondary intention" (from the inside out)

3. Takes 4–8 weeks for complete healing

Success rate: >90% for simple fistulas with low recurrence.

Which Procedure Is Right for You?

| Type of Fistula | Preferred Surgery |

|----------------|-------------------|

| Low, simple fistula | Fistulotomy (laying open) |

| High, complex fistula | Seton (staged procedure) |

| Crohn's-related fistula | Seton + medical management |

| Recurrent fistula | Advanced flap procedures |

Recovery After Surgery

Hospital stay: 1–2 days (for fistulotomy)

Wound care: Daily sitz baths, dressing changes for 4–8 weeks

Diet: High fibre, plenty of fluids

Activity: Light activities in 1 week; avoid heavy lifting for 4 weeks

Pain: Managed with analgesics; most significant in first 3–5 days

Possible Complications

Wound infection (uncommon with proper care)

Recurrence (more likely with complex fistulas)

Incontinence (rare with low fistulas; seton minimises this risk for high fistulas)

When to Seek Immediate Help

Increasing pain, swelling, or fever after surgery

Heavy bleeding from the wound

No improvement after 10 days

Iswarya Hospital's Colorectal Surgery team has extensive experience in the management of complex anal fistulas with sphincter-preserving techniques.

Tags:

#anal fistula#seton#fistulotomy#colorectal surgery#gastroenterology

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