Several aspects can influence whether a person is likely to develop an anal fistula. These include:

• History of Anal Abscesses: The most common precursor to an anal fistula is an untreated or recurrent anal abscess. People who frequently suffer from these abscesses are at a significantly higher risk of fistula formation. If the abscess doesn’t drain completely or is not treated on time, it can result in a chronic fistula tract.
• Inflammatory Bowel Diseases (IBD): People with conditions like Crohn’s disease and ulcerative colitis are at a greater risk. Crohn’s disease, in particular, causes chronic inflammation of the digestive tract, including the rectum and anal region. This inflammation can lead to the appearance of deep abscesses and, subsequently, fistulas.
• Tuberculosis and Other Infections: In regions like India, anorectal tuberculosis is another important cause of fistula-in-ano. TB can affect the gastrointestinal tract and lead to chronic, complex, and often multiple fistulous tracts. Similarly, infections caused by STDs, HIV, and other bacterial or parasitic infections can also increase the chances of fistula development.
• Poor Anal Hygiene: Maintaining adequate hygiene in the anal region is crucial. People who neglect cleanliness or have conditions that prevent proper cleaning (such as obesity or mobility issues) are at increased risk. Poor hygiene can lead to recurrent infections, which in turn contribute to abscess and fistula formation.
• Sedentary Lifestyle: A sedentary lifestyle, specifically prolonged sitting, improves the risk of developing anal abscesses and fissures, which can then lead to fistulas. Sitting for long hours creates pressure on the rectal area, reducing blood flow and contributing to infection-prone environments.
• Weakened Immune System: People with weakened immune systems, such as those undergoing chemotherapy, living with diabetes, or on immunosuppressant medications, may not heal properly from minor infections. These infections can worsen over time, ultimately forming a fistula.
• Smoking and Alcohol Consumption: Both smoking and excessive alcohol intake impair the body’s ability to heal infections. They compromise the immune system, interfere with blood flow, and raise inflammation—all of which contribute to the likelihood of developing anal fistulas.
• Genetic Predisposition: Some people may have a genetic tendency toward inflammatory or autoimmune conditions that contribute to anal fistula formation. While genetics alone doesn’t cause the fistula, it increases susceptibility when combined with other environmental or lifestyle triggers.
• Delayed or Inadequate Treatment: One of the leading causes of chronic anal fistulas is delayed diagnosis or improper treatment of perianal infections. Over-the-counter medications or home therapies might mask symptoms temporarily but fail to treat the root cause. As a result, an acute infection can develop into a chronic, complex fistula over time.