Anal Fistula

Learn more about Anal Fistula

Anal Fistula

An anal fistula is an abnormal passageway from the anal canal to the skin of the buttock.  It is a common consequence of a perianal abscess.

A fistula will act like a wound that doesn’t heal, close to the anus or on the buttocks. It may intermittently swell, and discharge blood or pus, or both. It can leak and discharge fluid, and occasionally gas will pass down the fistula track. 

A fistula is NOT a reflection of poor hygiene. The application of soaps and excessive cleaning will not aid the problem, and may do further harm to the skin. There are no over the counter creams or lotions that will help heal an anal fistula. 

A fistula is not likely to heal with antibiotics, and the treatment of an established fistula is usually surgery. 

Anal fistula diagram

Anal fistula treatment must be tailored to you.

The repair of a fistula can be challenging, as it is important to protect and preserve normal sphincter muscle function (those muscles which allow you to control your bowel motions or wind).

Treatment options for the fistula depend on the type of fistula, the degree of sphincter muscle involvement, and any risks the patient has of incontinence (a lack of bowel control).

A ‘simple’ fistula is most common. This is a fistula that is short, involves a small amount of muscle, and in a patient without extra risks for incontinence. A simple fistula is treated most often by a ‘fistulotomy’, or a cut down onto the track to open it up. The wound is then allowed to heal with time. 

A ‘complex’ fistula is more challenging for both the colorectal surgeon and patient. A complex fistula may involve a significant amount of anal sphincter muscle, have multiple tracks, or occur in a patient who already has an increased risk of incontinence. These risks may include a history of a tear with childbirth, Crohn’s disease, or a history of radiation treatment. 

A complex fistula may require additional workup – and sometimes your colorectal surgeon may use an ultrasound or MRI to help confirm clinical findings. 

The initial step in fistula management

The first step in fistula management is exploring the fistula in the operating theatre. At this point, treatment will proceed as discussed with you in the preoperative consultation.

A fistulotomy is performed if it is safe, in a simple fistula. In a complex fistula, inital management is often the insertion of a ‘draining seton’, a thin plastic cord which helps allow any infection to resolve. This is usually a temporary measure and allows control of the fistula, and for things to ‘settle down’. Further surgery will be required to achieve a repair. Some patients may choose to have a seton permanently. 

Operations that preserve muscle function need to be tailored to an individual patients specific circumstances, and your colorectal surgeon will discuss the possible treatments. Possible options include an anal fistula plug (see video below) fistula clip, ligation of intersphincteric fistula tract (LIFT), a rectal advancement flap (MAF/ERAF) and more.

Dr Morris has a special interest in anal fistulas. In your consultation about your fistula, you will receive a simple explanation of the problem, and the commencement of an individualised strategy to work to achieve healing with minimisation of risks.

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