What are the clinical symptoms and causes of anal fistula?
Jan 21, 2022
Source: Cainiu Health
Dr. Zhang Junfeng
Introduction
The clinical symptoms of anal fistula include one or multiple external openings visible around the anus, with persistent discharge of purulent fluid and/or serosanguineous fluid. The condition often fluctuates—improving and worsening intermittently. If an external opening closes spontaneously, an abscess may form, causing pain; however, once the abscess ruptures and the pus drains, the pain typically subsides significantly.
Patients with anal fistulas primarily develop inflammation and abscesses due to infections caused by *Mycobacterium tuberculosis* or *Actinomyces* species. Once an anal fistula develops, it not only causes multiple symptoms—including purulent discharge, pain, and bleeding—but also significantly impacts the patient’s overall health. So, what are the specific clinical causes of anal fistula formation?
Clinical Symptoms and Etiology of Anal Fistula
Anal fistula is a relatively common clinical condition that severely compromises both physical health and quality of life. It typically arises when perianal abscesses are inadequately treated and subsequently rupture, discharging pus and forming a fistulous tract.
Clinically, anal fistulas present as one or more external openings around the anus, with persistent, intermittent discharge of purulent or serosanguineous fluid. Symptoms may fluctuate—improving temporarily before worsening again. When an external opening heals spontaneously, an abscess may recur, causing significant pain; however, once the abscess ruptures and drains, the pain usually subsides markedly.
Based on clinical presentation, anal fistulas are classified as either low-lying or high-lying. According to the configuration of internal and external openings, they are further categorized as simple or complex fistulas.
In clinical practice, perianal abscess is considered the primary precursor to anal fistula. The pathogenesis involves fecal stasis in the anal crypts, leading to local infection and subsequent development of a perianal abscess. Many patients fail to seek timely treatment, allowing the disease to progress: the abscess eventually ruptures externally, and the surrounding tissue—including the external opening or surgical incision site—undergoes progressive fibrosis and connective tissue proliferation, ultimately forming a rigid, tubular wall—the fistula tract.
Given the substantial morbidity associated with anal fistulas, preventive measures should be prioritized by everyone in daily life. Individuals with pre-existing anorectal conditions, in particular, must cultivate healthy lifestyle habits and actively manage and treat their underlying conditions.
We hope the above information is helpful to you. Wishing you good health and happiness!
