Perianal Fistula

Mr Ranchod undertook advanced fellowship training at St Mark’s Hospital, London, gaining additional experience in the assessment and multidisciplinary management of complex perianal fistula disease, including Crohn’s-related fistulae and sphincter-preserving treatment strategies. This experience complements his contemporary colorectal practice in Melbourne.

Perianal fistulae most commonly develop following a perianal abscess that has not healed completely. They are classified by their relationship to the anal sphincter complex, and may be simple (low, involving little sphincter) or complex (high, branching, recurrent, or anterior in women).

A subset of fistulae are associated with Crohn’s disease, where management is shared between colorectal surgery and gastroenterology. Other contributing factors include previous pelvic surgery, radiotherapy and obstetric injury.

Symptoms are often longstanding and may fluctuate over months or years.

• Persistent or intermittent discharge from an opening near the anus.
• Recurrent perianal abscess or swelling.
• Perianal pain, particularly with sitting or bowel motions.
• Skin irritation around the anus.
• Bleeding or staining of underwear.

Assessment begins with a careful history and examination. Most patients with a suspected complex fistula require an MRI of the pelvis to map the fistula tract and its relationship to the sphincter complex, and an examination under anaesthetic to confirm anatomy and place a draining seton where appropriate.

For patients with suspected or known Crohn’s disease, colonoscopy and gastroenterology input are coordinated as part of multidisciplinary care.

Treatment is tailored to the anatomy of the fistula, the underlying cause and the patient’s continence. Simple low fistulae may be managed with a straightforward operation. Complex fistulae are typically managed in stages, initially a draining seton to settle infection, followed by a definitive sphincter-preserving procedure such as a LIFT procedure, advancement flap or other technique appropriate to the anatomy.

In Crohn’s-related disease, surgical treatment is integrated with medical therapy, with the goal of controlling symptoms, preserving continence and avoiding repeated unsuccessful interventions.

Recovery depends on the type of procedure performed. Many fistula operations are performed as day or short-stay procedures. Wound care, sitz baths and a structured follow-up plan are provided. For complex disease, treatment may extend over several months as the fistula is brought under control and then definitively addressed.