<Anal Fistula>

What is Anal Fistula?

Anal fistula is a tiny inflammatory tract connecting anal skin with the rectal wall. This tract is formed after the acute infection and abscess formation of the anal crypt gland.

Causes

Anal fistula is mainly caused by purulent bacterial infection. Some anal fistulas are resulted from anal fissure, post hemorrhoidectomy wound, Crohn's disease, ano-rectal trauma secondary infection or malignancy.

Symptoms

  • Painful anal lump with increased temperature and redness
  • Varying size of lump
  • Secretion of smelly, pus-like or blood-stained discharge
  • Skin irritation around the anus
  • Difficulty and pain in sitting or passing stool

Diagnosis

Experienced surgeons will ask a complete history from you and perform a physical exam around the anus and inside the anus. Proctoscopy is often used during bedside examination. MRI perianal assessment is often used to confirm the diagnosis of anal fistula. Colonoscopy may be necessary if Crohn's disease is suspected.

Treatment

Fistulectomy or fistulotomy are the most common surgeries to treat anal fistula. The anal fistula surgery is often performed under general anesthesia or spinal anesthesia. During surgery, experienced surgeons will:

  1. Find the external opening in the skin around the anus.
  2. Find the internal fistula opening by inserting a probe or H2O2 instillation from the external opening along the fistula tract. The whole fistula tract can then be cut, laid open, or removed.
  3. Try to preserve the anal sphincter and prevent fecal incontinence.
  4. Inject a long-acting local anesthetic agent into the wound to reduce postoperative pain.

After surgery, patients need to take painkillers and laxatives. Patients need to clean the wound after bowel movements or showers. Topical local anaesthetic agents may be used over the wound to reduce pain. The anal fistula wound will usually heal gradually in 4-12 weeks.

There are many different surgeries to treat anal fistulas. The chances of recurrence of different types of anal fistula surgeries range between 7% and 50%.

FAQs

Q: Will anal fistula heal with medicine alone?

A: No.

Q: If I have anal fistula and I refuse surgery, what will happen?
A: The situation will become worse. An anal fistula can cause repeated infection, abscess formation and abscess rupture. Sometimes, side tracts will form and it may result in a bigger surgery, a more difficult surgery, prolonged downtime, and slow recovery. If you have an anal fistula, delaying treatment is really unwise. Please seek advice from your surgeon.
Q: Who should I see if I suspect myself having an anal fistula?
A: General Surgeons.