An anal fistula is a little tunnel that links an abscess, an infectious cavity in the anus, to an opening on the skin around the anus. The anus is the external opening through which feces are an exit from the body. Just inside the anus are several small glands that create mucus. Occasionally, these glands get collapsed and can become infectious, leading to an abscess. About half of these abscesses may promote into a fistula.
Causes of an Anal Fistula
The significant reasons for an anal fistula are injured anal glands and anal abscesses. Other, much less usual, situations that can make an anal fistula include:
1) Crohn’s disease (an inflammatory disease of the intestine)
2) Radiation (treatment for cancer)
4) Sexually transmitted diseases
6) Diverticulitis (a condition in which small pouches form in the large intestine and become inflamed)
Symptoms of Anal Fistula
The signs and symptoms of an anal fistula include:
1) Frequent anal abscesses
2) Pain and swelling around the anus
3) Bloody or foul-smelling drainage (pus) from an opening around the anus. The pain may reduce after the fistula attacks.
4) Irritation of the skin around the anus from drainage
5) Pain with bowel movements
7) Fever, chills and a general feeling of fatigue
You should consult your doctor if you observe any of these symptoms.
How is an Anal Fistula diagnosed?
The doctor can generally diagnose an anal fistula by testing the area around the anus. He or she will observe for an opening (the fistula tract) on the skin. The doctor will then try to recognize how deep the track is, and the direction in which it is passing. In many cases, there will be a tunnel from the external opening.
Some fistulas may be invisible on the surface of the skin. In this situation, your physician may require to perform additional tests:
1) An anoscopy is a process in which a particular instrument is used to observe inside your anus and rectum.
2) The physician may also order an ultrasound or MRI of the anal area to take a better view of the fistula tract.
3) Sometimes the surgeon will require to test you in the operating room (called test under anesthesia) to analyze the fistula.
If a fistula has arisen, the physician may also want to do further tests to observe if the situation is associated with Crohn’s disease, an inflammatory disease of the intestine. About 25% of people with Crohn’s disease promote fistulas. Among these studies are blood tests, X-rays, and colonoscopy. A colonoscopy is a process in which a flexible, lighted instrument is placed into the colon via the anus. It is worked under conscious sedation, a type of light anesthetic.
Treatments for Anal Fistula
Surgery is almost always needed to cure an anal fistula. The operation is performed by a colon and rectal surgeon. The aim of the surgery is a balance between getting rid of the fistula while covering the anal sphincter muscles, which could make incontinence if injured.
In the case of a more critical fistula, the surgeon may have to insert a select drain called a seton, which exists in place for at least 6 weeks. After a seton is added, a second operation is almost always performed:
1) A fistulotomy or
2) An advancement flap process (the fistula is covered with a flap, or piece of tissue, taken from the rectum, like a trap door), or
3) A lift process (the skin above the fistula is opened up, the sphincter muscles are spread, and the fistula is tied off).
A new treatment for Crohn’s disease fistulas is to push stem cells into the fistula. The colorectal surgeon will discuss all of the options before the surgery.
Fistula surgery is generally done on an outpatient basis, which means the patient can go home on the same day. Patients who have very large or critical fistula drains may have to stay in the hospital for a short time after the surgery. Some fistulas may need various operations to get out of the fistula.