The pathology of abscesses and fistulas
BETTER UNDERSTANDING, BETTER HEALING!
An anal fistula begins as an anal abscess. A small gland in the anal canal becomes blocked, infection sets in and the abscess forms.
This is what an anal abscess looks like…
The boundary between the cutaneous area (lower area) and the mucous area (upper area) of the anal canal takes on a scalloped appearance: this boundary is called the pectineal line.
In the hollow of the undulations of the pectineal line, there are small glands whose branches cross the internal sphincter into the intersphincteric space.
When the duct of a gland becomes blocked, this creates an infection that first lodges between the two sphincters: this leads to an intersphincteric abscess.
Spontaneous or surgical drainage of the abscess on the skin results in a fistula, which is an abnormal path between the anal canal and the skin.
The most common pathway is intersphincteric (b) followed by the transsphincteric pathway (c), as shown in this diagram from the Mayo Clinic.
Submucosal fistula (a) is uncommon and usually results from an anal fissure that has become complicated.
Other varieties are even more uncommon: supra-sphincteric (d) and extra-sphincteric (e). They are associated either with a disease of the rectum (e.g.: Crohn’s) or with a surgical error.
How to treat abscesses and fistulas
An abscess
An abscess usually requires drainage. This may occur spontaneously. The patient will notice a discharge of pus from an opening that has developed, which is usually accompanied by pain relief. In the absence of spontaneous drainage, most abscesses require surgical drainage, usually done in an emergency room (hospital) under local anesthesia or in the operating room under some other form of anesthesia. On occasion, an abscess that is in its early stages (abscess in formation) is treated with antibiotics alone.
A fistula
An anal fistula will usually require day surgery (in a hospital setting). The doctors at the Procto Clinic will be able to discuss with you the need for such an intervention, explain it to you and indicate the associated risks.
They can then complete an application for admission for this procedure.
Practical tips
In order to help you, we have put at your disposal several useful tips.
