What is a fistula and what are the causes
of its development
Before focusing on anal fistulas, specifically those treated in the proctology field, it is helpful to provide an introduction to better understand what fistulas are, the different types that exist, and the locations where they more commonly occur. The term “fistula” refers to a pathological lesion, tubular in shape, that creates a connection between the source of infection and the surrounding skin. A fistula is the chronic evolution of an abscess, which is the acute phase of an infection originating in microscopic glands located within the anal canal. It presents as a localized collection of pus, varying in depth.
At the peak of inflammation, the abscess collection ruptures, allowing the pus to drain. Once absorbed, the pus creates a pathway that traverses the various structures affected by the inflammation, thus forming the fistula. Fistulas rarely heal spontaneously. Typically, they tend to become chronic, particularly when they continue to be fueled by infection and inflammatory materials that caused their formation, or when there is passage of biological substances produced by our body, such as saliva, urine, and fecal material.
Classification of fistulas
Fistulas are classified into numerous categories, with the most commonly used classification being based on the path they take:
- internal or external: fistulas are internal when they connect two organs or internal cavities within the body, and external when they connect one or more cavities to the outside.
- simple or complex: fistulas are considered simple if they consist of a single channel, and complex or branched if they have multiple communication channels.
- complete or incomplete: fistulas are complete when the communication between the two cavities is intact,
and incomplete when the canal is not yet fully formed.
Body areas most commonly affected by fistulas
Fistulas can form in any organ or body cavity, but the most frequently encountered ones are:
- ANORECTAL FISTULA: connects the anal canal (or, less commonly, the rectum) to the perianal skin.
- SACROCOCCYGEAL FISTULA: this type of fistula connects the anus to the coccygeal area and is usually
recurrent and multiple, with multiple tracts. - CHOLECYSTODUODENAL OR CHOLECYSTOCOLIC FISTULA: formed when the gallbladder (filled with stones and inflamed) adheres to the duodenum or colon and perforates, resulting in the formation of a fistula through which stones can pass and be expelled with feces.
- RECTOVAGINAL, ENTEROENTERIC, RECTOVESICAL, AND ENTEROVESICAL FISTULAS: these types of fistulas occur between the intestines or between the rectum and bladder or vagina. They develop when the intestines are inflamed due to conditions such as Crohn’s disease or carcinomas.
Symptoms of a fistula
The symptoms associated with fistulas can vary significantly depending on the location and size of the specific fistula. The most common manifestations include:
- Pain
- Swelling
- Pus drainage
- Bleeding
- Fever
- Foul odor.
Diagnosis and treatment
Fistulas present a complex problem as they can be associated with a wide range of situations and can develop in the presence of various conditions. Regardless of their location, fistulas require specialized medical attention, and the situation should never be underestimated. Prompt action is essential, and due to the complexity of the issue, an interdisciplinary approach is typically taken. The treatment of fistulas involves pharmacological, surgical, and combined therapeutic strategies. There is no one-size-fits-all therapy for all patients with this condition. The choice of treatment depends on various factors, such as the site of occurrence, type, severity, and associated complications.
Next month, we will continue exploring fistulas, focusing on anorectal fistulas. We will examine the factors that can predispose their development, the proctological evaluation process, and finally, the treatment options.
The contents of this page are for informational purposes only and should in no way replace the advice, diagnosis, or treatment prescribed by your physician. Responses to the same treatment may vary from patient to patient. Always consult your doctor regarding any information related to diagnoses and treatments, and meticulously follow their instructions.
