What is anal fistula? Know the symptoms of anal fistula early

Anal impotence is relatively common in clinical practice, but many people still don’t know what anal impotence is. Anal fistula is also called anorectal fistula, which mainly invades the anal canal. There are many causes of anal impotence, including bacterial infection. Surgical infection can also cause anal impotence.

1. Pathological concept

Anal fistula refers to a tube that should not be connected between the anal canal and rectum around the anus and the outside world. It is generally composed of three parts: the inner opening, the fistula, and the outer opening. The inner opening is mostly located in the lower part of the rectum or the anal canal, and there is usually one; the outer opening is on the perianal skin, and there are one or more. It does not heal for a long time or recurs intermittently. Anal fistula is one of the common rectal and anal canal diseases. It can occur at any age, especially in young and middle-aged men. Most anal fistulas are caused by bacterial infection in the anal crypts, which causes abscesses in the perianal space. After the abscess ruptures, the abscess cavity shrinks and does not heal for a long time. Therefore, the inner opening is mostly at the anal sinus on the dentate line. The abscess ruptures on its own to form an outer opening, which is located on the perianal skin. Because the outer opening occurs quickly, the abscess often heals falsely, resulting in repeated rupture of the abscess to form multiple fistulas and outer openings, turning a simple anal fistula into a complex anal fistula. The fistula is surrounded by reactive and dense fibrous tissue, and the near-lumen part is inflammatory granulation tissue, which can be epithelialized in the later stage.

2. Symptoms

The early stages of anal impotence are mainly characterized by abscess and inflammation. As the inflammation subsides, the anal fistula gradually forms and the local symptoms gradually ease. However, in cases of complicated anal fistula or acute infection, there will be obvious local inflammatory reactions and systemic symptoms. In the chronic stage of anal fistula, a small amount of purulent, bloody, and mucous secretions may be discharged from the external opening of the fistula. There is generally no pain or only discomfort in the anus. Examination can feel a hard cord-like object at the edge of the patient's anus, and pus will overflow from the external opening or anus when pressed. During an acute attack, there is obvious local redness, swelling, heat, and pain, and systemic symptoms such as low-grade fever, weakness, and loss of appetite may also occur.

3. Reasons

Specifically, the causes of anal fistula include: anal injury caused by trauma that has not healed, anal fistula caused by bacterial infection, perianal abscess that has not received timely and effective treatment, after the pus ruptures, the abscess cavity shrinks and causes anal fistula, and perineal surgery, internal hemorrhoids are injected too deep, or there is infection after surgery, etc., which can all cause anal fistula.