An anal fistula (also called a fistula-in-ano) is a small tunnel or communication channel that develops between the skin around and rectum anal fistula as a result of an infection or a collection of pus (abscess) in or around your anus. The anus is the external opening through which faeces are expelled from the body. Just inside the anus are a number of small glands. If one of these glands becomes blocked, an abscess or an infected cavity may form. An anal abscess is usually treated by surgical drainage, although some drain spontaneously. About 50% of these abscesses may develop into a fistula, in which a small tunnel connects the infected gland inside the anus to an opening on the skin around the anus. Anal Fistula can be higher or lower depending on whether and where they pass through the anal sphincter muscles.
Low fistula may not pass through the sphincter muscles at all, or go through in their lower half.
High fistula passes through the upper half of sphincter muscles.
Fistula can be single tract or multiple tract. A simple fistula has a single tunnel running from your rectum to your skin and is usually a low fistula. If you have a complex fistula it may have branches, have more than one opening, or be very high up. Complex fistulas are more difficult to treat. Symptoms and signs of anal fistula can be constant or may disappear for a time before coming back.
An obstetric fistula is a connection between the vagina and rectum or bladder that is caused by prolonged obstructed labor, leaving a woman incontinent of urine or feces or both. For women with obstructed labor, labor that goes unattended, the labor can last up to 5 or 6 days. The labor causes contractions that push the baby’s head against the mother’s pelvic bone. The soft tissues between the baby’s head and the pelvic bone are compressed and do not receive proper blood flow. The lack of blood flow causes this delicate tissue to die and where it dies holes are created between the laboring mother’s bladder and vagina and/or between the rectum and vagina.
When an abnormal channel forms between an artery and a vein, blood bypasses capillaries and flows directly into a vein from the artery. This form of fistula may be congenital or acquired after birth. Congenital arteriovenous fistulas are very rare, but the acquired form may be caused by injury to a vein and artery lying side by side. Usually, the injury is caused by a piercing wound such as from a bullet or from some other sharp objects like knife.
A fistula that has formed in the wall of the vagina is called a vaginal fistula. A vaginal fistula generally starts with some kind of tissue damage. After few days to months of tissue breakdown, a fistula opens up. In general vaginal fistula happens after :-
☛ Surgery of the back wall of the vagina, the perineum, anus, or rectum.
☛ Due to IBD, Crohn’s disease & ulcerative colitis.
Depending on the origin and connectivity it is classified as :-
☛ A vaginal fistula that opens into the urinary tract is called a vesicovaginal fistula.
☛ A vaginal fistula that opens into the small bowel is called a enterovaginal fistula.
☛ A vaginal fistula that opens into the rectum is called a rectovaginal fistula.
☛ A vaginal fistula that opens into the colon is called a colovaginal fistula.
☛ Extrasphincteric fistula begins from the rectum and proceed downward, through the anal muscle and open into the skin surrounding the anus. This type does not arise from the dentate line (where the anal glands are located). Causes of this type could be from a rectal, pelvic or supralevator origin, usually secondary to Crohn’s disease or an inflammatory process such abscesses.
☛ Suprasphincteric fistula begin between the internal and external sphincter muscles, extend above and cross the puborectali muscle, proceed downward between the puborectalis and levator ani muscles, and open an inch or more away from the anus.
☛ Transphincteric fistula begin between the internal and external sphincter muscles or behind the anus, cross the external sphincter muscle and open an inch or more away from the anus. These may take a ‘U’ shape and form multiple external openings. This is sometimes termed a horseshoe fistula.
☛ Intersphincteric fistula begin between the internal and external sphincter muscles, pass through the internal sphincter muscle, and open very close to the anus.
☛ Submucosal fistula pass superficially beneath the submucosa and do not cross either sphincter muscle.
An anal fistula is frequently the result of a previous or current anal abscess. This occurs in up to 50-60% of patients with abscesses. Normal anatomy includes small glands just inside the anus. The fistula is the tunnel that forms under the skin and connects the clogged infected glands to an abscess. In general fistula is a reason of :-☛ Anal Abscesses.
☛ Crohn’s disease and Tuberculosis.
☛ Due to Cancer & Sexually transmitted diseases (STD).
☛ Due to long & untreated inflammatory bowel syndrome (IBD’s).
☛ Sometimes for not maintaining Anal Hygiene.
The following may be symptoms or signs of an anal fistula:
☛ Recurrent anal abscesses.
☛ Skin irritation around the anus, including swelling, redness and tenderness.
☛ Constipation or pain associated with bowels.
☛ Bloody or foul-smelling drainage (pus) from an opening around the anus. The pain may decrease after the fistula drains.
☛ Fever, chills, and a general feeling of fatigue.
You should see your physician if you notice any of these symptoms.
Your Doctor can usually diagnose an anal fistula by examining the area around the anus, specifically for any external opening on the skin. If this is visible, then its depth and direction will be found out. Often drainage can be produced from the external opening. Some fistulas or blind fistulas may not be visible on the skin's surface. In this case some additional tests line endoscopy, ultrasound or MRI is required for proper identification & orientation of the fistula tract. Some of the common diagnosis techniques are :-
☛ Fistula probe– This is a fine, narrow instrument which is specifically designed to be inserted though a fistula tract.
☛ Anoscope- this instrument is well lubricated and is passed a few inches into your rectum (end of large intestine). An anoscope has a light on the end, which allows the Doctor using it to see the entire anal canal. In case of complicated & higher end fistula, your doctor may recommend further tests, which may include:
☛ Diluted methylene blue dye- this dye is injected into the fistula and it helps to show your doctor the fistula's position and path. The dye very rarely causes any side effects.
☛ Fistulography- this involves having a special solution injected into your fistula. You will then have an x-ray, which shows the path of the solution as an x- ray image.
☛ Magnetic resonance imaging (MRI) scan- this scan uses magnetic and radio waves to get a detailed images of the fistula tracts & there length diameter & orientation.
The type of fistula treatment or surgery depends on the position of fistula. The treatment options include:
☛ Fistulotomy:This fistula treatment is among the most common option & used in 80-90% of cases. Fistulotomy involves cutting open the whole length & diameter of the fistula in order to flush out the infected contents. Healing process is slow & takes 1-2 months associated with antibiotics & pain killers.
☛ Seton treatment and techniques :A seton is a piece of thread which is left in the fistula tract. This fistula treatment is advisable when there is a high risk of developing incontinence when the fistula crosses the sphincter muscles. Sometimes repeated operations are necessary.
☛ Advancement flap procedure :Very helpful treatment in complex fistula, or is there is a high risk of incontinence. Basically advancement flap is a piece of tissue that is removed from the rectum or from the skin around the anus. During surgery, the fistula tract is removed and the flap is reattached where the opening of the fistula was.
☛ Fibrin glue :This fistula treatment is a non-surgical treatment option. Special glue is injected into the fistula to seal the tract, then the opening is stitched closed. This fistula treatment is simple, safe and painless procedure & can be done very less time. Initial success rates are high (up to 70%) however long term chances of recurrence are very high & success rate dips up to (10%) after 1-2 years.
☛ Bioprosthetic plug :This fistula treatment is a cone shaped plug made from human tissue; it blocks the internal opening of the fistula. Stitches keep it in place. However, fistula is not sealed completely & partially kept open, so that it can continue to drain. New tissue usually grows around the plug to heal the fistula. Generally the success rates are of over 80% but long term recurrence rates are more.
☛ You might feel sore after having anal fistula treatment and surgery; you can take over-the-counter painkillers such as paracetamol or ibuprofen for pain relief. Recovery from Anaesthesia may take 24 hours also so don't drive, drink alcohol & operate any machinery.
☛ Generally surgery wounds should heal within six weeks. Try to take complete rest & make sure to keep it clean and reduce any chance of infection Your doctor may suggest for warm baths several times a day to relieve any pain.
☛ When bathing, use warm water and soft cotton wool instead of sponges & avoid using any strong smelling or perfumed soaps. Pat the area dry rather than rubbing it. You can wear a sanitary pad to prevent any leakage from the wound staining your clothes & also for your general comfort.
☛ Sitting on a comfortable & soft cushion can ease any discomfort, also try to wear loose fitting clothes and under garments.
☛ Try to have a high fibre diet, increase your fluid intake or take a laxative to keep your bowels regular & soft for easy passage. Always consult your doctor in case of any odd conditions or observations.
Even though there are lot of advance fistula treatment and techniques like VAAFT (Video assisted anal fistula treatment) are there, still there are various side effects or risks are associated with fistula surgery. The level of risk also depends on the location of fistula & the specific technique also.
☛ Infection – this requires administration of antibiotics courses, severe cases may need to be treated in hospital also.
☛ Recurrence of the fistula – the fistula can sometimes recur despite surgery.
☛ Bowel incontinence – this is a potential risk with most types of anal fistula treatment, although severe incontinence is rare and every effort will be made to prevent it.
Varicose veins in ano-rectal region make anal canal narrower, constricted & inflamed, thus causing friction between faeces & anal canal. This prolong interaction causes high degree of inflammation which blocks the anal glands located between the internal and external anal sphincter. When the outlet of these glands becomes blocked, an abscess can form which can, in long run stretch out to the skin surface. The tract created by this procedure is known as fistula.
Till now open surgery is considered as a most doable process of treating fistula-in-ano, however it is having a least success rate of just 40-60 %. Repeated surgeries can increase the length & diameter of fistulous tract & therefore makes them very difficult to cure.PF2-CURE®is a unique ayurvedic formulation that helps in drying, reducing & finally closing the fistulous tracts in ano-rectal region, simply by opening the blockage of anal glands. Major functions of PF2-CURE® are:
☛ Opens the Anal-glands blocked due to varicoseveins inflammation.
☛ Creates venous sufficiency (in ano-rectal region).
☛ Acts as a cooling agent on gastrointestinal tract.
☛ Acts as Anti-infective agent.
☛ Acts as Anti-inflammatory agent.
☛ Acts as a digestive aid.
☛ Acts as a Stool Softener.
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Reviewed by Chandrakant, Neelam Rana, Swati Agrawal, Mitisha Valecha, Pratigya Singh & Ayushmaan Health Content Team, Feb-2018. Peer reviewed by Dr D.K Sharma (Physician) & Dr.Ashok Sharma (BAMS)