Anal fistulas are small abscess or infected cavity is formed due to blockage of certain glands of the anus. Anus is the end portion of the digestive tract through which feces are expelled. The passage between the muscular opening of the anus and the skin gets infected to form an abscess. Anal fistulas are caused by abscess and it can cause pain during bowel movements with bleeding. It can be treated by surgery.
Anal abscess is the major cause for the formation of anal fistulas. In some people Crohn’s disease or sexually transmitted disease can cause anal fistulas. Even infectious disease like tuberculosis or sudden trauma can trigger to form an abscess leading to anal fistulas.
Some of the signs of anal fistulas include formation of anal abscess, bleeding, pain during bowel movements, inflammation around the anus and pus drainage with foul smell is seen from the small opening of the anus. Some people may develop fever and fatigue.
Anal fistulas can cause irritation of the skin surrounding the anus and a throbbing pain which increases when the person sits down or coughs. Often it can cause bleeding while making bowel movements. In case you have developed anal fistulas due to Crohn’s disease you can have symptoms like diarrhea, loss of appetite, nausea, vomiting and weight loss.
Your doctor will examine the anal region closely to check if there is any external opening of the skin in that region. He would then find out the depth of the fistula. In some cases he would use special device called anoscopy to view the inner portions of anus. He may order for other tests like ultrasound or MRI scan of the anal/rectum area. To check if the fistulas are formed due to Crohn’s disease he may order for series of tests like blood test, X-ray and colonoscopy to determine if there is inflammation of the intestine.
- Anal fistula can be either simple type (when there is only one fistula tract) or complex type (if there are multiple connections) and it can be placed low or high position.
- Based on the location of fistulas over the sphincter muscles, they are classified into two types.
- If the fistula tract crosses the sphincter muscles to open on the skin surface next to anus, it is called Intersphincteric fistula.
- Sometimes, fistulas cross both internal and external sphincter muscles to form trans-sphincteric fistula.
Anal Fistulas Treatment :
Various methods of treatment are available for anal fistulas. The mode of treatment varies with that of the location of the abscess. The ultimate aim of treating fistulas is to drain the abscess and prevent further occurrence.
- Fistulotomy :
This is the procedure in which the surgeon cuts open the fistula and drains the abscess along with infected tissue. He would then fix it in place by sutures. In more severe cases the surgeon would remove some portion of infected channel.
- Rectal Flap :
A flap or covering is created out of the rectal wall. The fistula is then opened and repaired and the flap is gently placed over the area to close the repair.
- Seton Repair :
Your surgeon would place a seton or silk string directly into the fistula so that it helps in draining the pus. In some cases special glue made out of fibrin or collagen is injected into the fistula’s opening and sealed. If the fistula is located between the two sphincter muscles, the surgeon would complete the process in two stages. In the first session, a seton is placed into the fistula and after few weeks, the infected tissue is removed and the opening is closed.
Often, surgery for anal fistula is done on outpatient basis and only for severe cases the patient will be hospitalized. You can feel some pain/discomfort on the anal region after surgery. Follow the instructions of your surgeon in taking medications for managing pain. You can sit on a warm bath for few minutes daily and use laxatives for some days to avoid straining while passing stool.