What Causes an Anal Fistula?
An anal fistula often develops in connection with a collection of pus in the anal area, an anal abscess. However, anal fistulas can also occur on their own. An anal fistula usually arises as a direct result of inflammation in the area of the proctodeal glands. These glands are located at the transition from the colon mucosa to the anal canal – the last section of the digestive tract. The body isolates this abscess or pus collection with so-called granulation tissue, forming an abscess capsule around the pus focus. The anal abscess spreads in the direction where the tissue offers the least resistance. In this way, a fistula tract forms, which, as soon as it breaks through to the skin surface, can continuously discharge secretions or pus. Because these fistula tracts can vary greatly, anal fistulas are also divided into different types depending on their location and relation to the anal sphincter muscle. For the correct treatment of anal fistulas, the location, severity, and course of the fistula, and thus the diagnosis and examinations by a doctor, play a central role.
Anal fistulas often also develop after anal diseases such as an anal fissure or after injuries in the anorectal area. This can be caused by sexual practices such as anal intercourse, but also, for example, by swallowed fish bones or toothpicks. Often, a small tear in the skin or mucosa of the anus, a so-called anal fissure, is the cause of an anal fistula. If such a lesion of the anal mucosa becomes infected, the infection can penetrate deeper into the tissue. This can also lead to the formation of an anal fistula that penetrates the sphincter muscle and also causes anal abscesses. Individual anatomical conditions, such as deepened crypts or anal pockets, can also lead to stool accumulation in these areas and thereby cause inflammation of the proctodeal glands.
Which Diseases Most Commonly Lead to Anal Fistulas?
There are various diseases and factors that increase the risk of an anal abscess and an anal fistula. Most anal fistulas are due to anal abscesses. However, besides inflammation of the proctodeal glands, anal fistulas can also especially arise from chronic inflammatory bowel diseases such as ulcerative colitis or Crohn's disease. Diabetes mellitus, diseases of the blood-forming system (e.g., leukemias), as well as diseases associated with immune deficiency (HIV infection) should also be considered in the medical history, diagnosis, and cause investigation of anal fistulas. Read more here about the symptoms of an anal fistula or about diagnosis and examinations in our blog post Anal Fistula Doctor.
What Risk Factors Exist for the Cause of an Anal Fistula?
According to the latest findings, there are several risk factors that promote anal fistulas. These risk factors can individually or in combination increase the risk of developing an anal fistula. By avoiding or controlling these factors, you can help reduce or even prevent anal fistulas. Besides diseases such as chronic inflammatory bowel diseases, diabetes mellitus, immune deficiency, and blood diseases, various lifestyle habits like smoking or prolonged sitting can increase the likelihood of developing an anal fistula. Therefore, we provide an overview here of various risk factors for the development of anal fistulas that you can consider in your daily life:
- Excessive consumption of heavily spiced foods, which can further irritate the sensitive rectal area.
- Lack of physical activity and prolonged sitting, as this leads to reduced blood circulation and increased pressure in the anal area.
- Spending extended time on the toilet during bowel movements, which increases pressure on the anal canal.
- Smoking and regular alcohol consumption, which can weaken the immune system and influence inflammatory reactions in the body.
- Lipid metabolism disorders, which can lead to fat tissue deposits in the body and increase the risk of inflammation.
- Psychosocial stress can impair immune function and thereby intensify inflammation in the body.
- Overweight (obesity) can increase pressure in the anorectal area and lead to circulatory disorders.
- Diabetes (sugar disease) can impair wound healing and increase the risk of infections.
- Skin diseases that make the skin around the anus more sensitive and increase the risk of inflammation.
- Increased daily salt intake, which leads to dehydration and can also impair intestinal health.
Read more here about the treatment of anal fistulas, or about the treatment of anal fistulas with suppositories. It is also important to inform yourself about the prevention of anal fistulas and the symptoms of anal fistulas.
