Anal fistula

What is an anal fistula?

An anal fistula is a narrow tunnel between an infected gland in the anorectal region to the skin surrounding the anus (perianal skin). Fistulas are a result of an accumulation of pus or abscess in the tissue close to the anus. Patients with this condition generally report discomfort, inflammation, skin irritation and pain in the anal region. Anal fistulas need medical intervention and do not heal by themselves. Most treatment for fistulas involves surgery and medication.

The human body excretes faeces through the external opening called the anus. The anal region contains numerous glands in small sizes that secrete mucus. It is possible that these glands can be clogged, which eventually leads to infection. The infection causes pus to form which leads to an abscess. Nearly 50% of these abscesses have the possibility of developing into a fistula.

Many people get confused between anal fissures, fistula, and hemorrhoids. Read in detail about them to know the exact causes, symptoms, and treatment.

Symptoms of an anal fistula

The following symptoms give an indication of the presence of an anal fistula :

• Pain while having a bowel movement
• Irritation in the skin around the anal region
• Pus and blood in the stools
• Foul smelling discharge from the anal area
• Discomfort and nagging pain that increases with movement. Severe pain while sitting, sneezing or coughing.
• Regular abscess in the anal area
• Inflammation and redness in the anal area
• Fever especially with an abscess
• In rare cases, bowel incontinence also occurs
• Hole on the skin near the anus, which marks the end of the fistula and is visible during physical examination
• Fatigue

Take a medical opinion in case you suffer from any of the above symptoms.

What are the important causes behind anal fistula?

The anus contains many glands that produce fluid. There is a possibility that these glands can be clogged. The clogged glands can result in the growth of bacteria and the accumulation of fluid. This can lead to inflamed tissue, which is medically called an abscess.

An untreated abscess develops into a fistula. Usually, when the abscess does not heal, it needs to find a way to drain out the infected fluid or pus. This will punch a hole on the skin near the anus to drain the pus out. The fistula is a tunnel that attaches the gland to the opening on the skin in the anal region.

Although the leading cause of anal fistula is blocked anal glands and abscess, yet sometimes they can develop due to the presence of certain medical conditions or circumstances.

• Tuberculosis
• Sexually transmitted disease
• Cancer
• Crohn’s disease
• Trauma
• Radiation

What are the best methods adopted by medical specialists to diagnose anal fistula?

Not all fistulas are easy to spot. If your doctor suspects you have an anal fistula, a physical exam and a consultation to know your medical history will be the first few steps towards diagnosis.

During the medical examination, the doctor will check for pus and oozing. It is possible that the doctor conducts an internal anal examination by sticking a finger inside your anus.

A proctologist is equipped to perform few tests to have a confirmed diagnosis of anal fistula. The following tests may be conducted:

Anal ultrasound

In this process, high-frequency sound waves capture the surface of the anal canal in imaging forms

Proctoscopy

Doctors perform proctoscopy to view the opening of the tract in the anal canal. In this process, the proctologist uses a specialised telescope with an attached fistula probe, which helps view inside the rectum

MRI and CT scan

In the case of a complex fistula, doctors use MRI imaging to check the anatomy of the tract. Additionally, these tests can also help the proctologist evaluate the extent of inflammation of the anal lining.

You may need to consult a colon and rectal specialist. In some cases,  a colonoscopy is also recommended. A colonoscopy is conducted under anaesthesia.

What are some of the clinical features of an anal fistula?

Generally, anal fistula presents in two ways. Either it presents as irregular or constant discharge of blood, pus, mucus or faeces into the perineum or there is repeated anal abscess. During clinical examination, your doctor may find an external opening on the perineum. The external hole in some cases could be completely open or there could be a granulation tissue cover on it. Doctors conduct a digital rectal investigation and may find the presence of a fibrous tract beneath the skin. 

What are the types of anal fistula ?

There are four types of anal fistulas.

1. Complete Fistula – Has two openings one that opens internally and another externally
2. Horseshoe Fistula – This is close to the anus and has a semi-circular tract around the rectum
3. Blind Fistula – The opening is only one at the end and connects two structures
4. Incomplete Fistula – In this type of anal fistula, a tube begins from the skin that is shut on the inside and  does not have any connection with any  internal structure

What is the best form of treatment for anal fistula ?

Surgery is the best treatment option for anal fistula. Fistulas do not heal on their own. It is important to know all the treatment options available. Discuss with your surgeon about the potential risks of any procedure they advise. Most of the treatment procedures can be performed in a doctor’s clinic.

Doctors generally use a plug during the surgery to close a simple fistula  after cutting open the skin and muscle surrounding the tunnel. The opening heals faster this way.

In cases where the fistula is more complicated, the specialist uses a tube called the seton. This tube is put into the opening and it drains out the infected fluid before surgery. The position of the fistula is important. The decision to cut into the sphincter muscles (muscles in charge of opening and closing the anus) will depend on the position of the fistula. Though doctors try their best not to damage them, the surgery may hamper the ability to control bowel movements.

There are various procedures to treat anal fistula but the type of procedure is dependent on the position of the fistula. Initially, your doctor may need to conduct the preliminary examination under the influence of anaesthesia to decide the best way to treat anal fistula.

Some of the options in the treatment of anal fistula are listed below:

Fistulotomy

Fistulotomy is the common surgery for anal fistulas. During this procedure, doctors cut the complete length of the fistula. This way the fistula is fully opened up. It appears like a flat scar and promotes faster healing. This form of treatment is only possible if the fistula does not pass through much of the anal sphincter muscles. Doctors always want to minimise the risk of bowel incontinence.

Seton techniques

This technique is used by the surgeon if the fistula passes through a major part of the anal sphincter muscle. Initially, the surgeon may insert a seton.   During this procedure, a piece of surgical thread called a seton is left in the fistula for many weeks. The main intention is to keep the fistula open and allow it to heal. This method intends to avoid surgically cutting the sphincter muscles.

Doctors may employ loose seton or tight ones depending upon the nature of the fistula. Several procedures may be needed until the fistula completely heals. Each time they may open a tiny part of the fistula.

Advancement flap procedure

This procedure may be in the reckoning if the fistula happens to pass through the anal sphincter and the risk of bowel incontinence is very high with a fistulotomy.

In this procedure, the surgeon cuts and scrapes out the fistula. The hole where it enters the bowel is covered with a flap of tissue. The tissue is taken from inside the rectum. The rectum is the last part of the bowel.

The advancement flap procedure helps avoid cutting the anal sphincter muscles. Compared to a fistulotomy, this procedure does not enjoy a good success rate.

LIFT procedure

LIFT which is ‘ligation of the intersphincteric fistula tract ‘ is adopted as a  treatment for fistulas that pass through anal sphincter muscles. This procedure is used if surgeons feel that a fistulotomy is a risky option.

Surgeons make an incision in the skin above the fistula. Next, the surgeon parts the sphincter muscles and then the fistula is closed at both its ends and cut open. It remains flat.  This procedure has shown a good success rate although it is a recent procedure. We still need more statistics to prove its efficacy.

Endoscopic ablation

This procedure involves inserting a tube with a camera, called an endoscope in the fistula. Through the endoscope, an electrode is passed to close and seal the fistula. Endoscopic ablation enjoys a good success rate and is also considered very safe.

Laser surgery

A laser beam that emits laser fibre radically to seal the fistulas, is the core of this treatment procedure. This form of treatment is not risky. Laser-assisted technique is in fact considered to be highly effective in treating anal fistula. Patients recover faster without the need to make frequent visits to the hospital.

Fibrin glue

This type of treatment happens to be the only non-surgical method of treatment for anal fistulas.

During this treatment method, the surgeon injects glue into the fistula under the influence of anaesthesia. The glue works to seal the fistula and promotes faster healing. This treatment is not considered as effective as fistulotomy in the management of simple fistulas. The results may not be as far-reaching too. Surgeons select fibrin glue usually to treat fistulas that are passing through the anal sphincter muscles. Surgeons try to avoid cutting the anal sphincter muscles unless it is necessary.

Bioprosthetic plug

In this procedure, surgeons insert a bioprosthetic plug. This plug is shaped like a cone and is made of animal tissue. This plug is used to block the fistula opening. This procedure is mostly successful and is also considered fairly safe.

What are the most significant risks of anal fistula surgery?

Treatment for anal fistula, like other forms of treatment, carries few risks of complications.  The extent of risks will largely depend on the position of the fistula and the type of surgical procedure undergone. Before you decide on the treatment option, always know the risks and complications of the surgical procedure envisaged.

The risks hover mainly around infection post-treatment or major side effects. Complications post-surgery can include adverse reactions to the anaesthetic, bleeding and risk of infection.  

Some of the major risks of fistula surgery are as follows:

• Prolonged healing time post-surgery: Most wounds heal within 6 weeks of surgery. In some cases, wounds may take longer to heal and this is one of the risks of surgery for anal fistula.
• Difficulty in bowel movements due to narrowing of the anal canal
• Infection – The risk of infection after the surgery to treat anal fistula cannot be ruled out. Doctors usually treat any infection with a course of antibiotics. If the infection is severe, the patient may require hospital admission.
• Relapse or reappearance of fistula – even though surgery was performed, sometimes the fistula can resurface.
• Bowel incontinence or losing the control over bowel movement – This is a real risk present with most forms of treatment for anal fistulas. In very rare cases, patients suffer severe bowel incontinence.

What are the steps to follow for post-operative care and recovery?

The recovery time after a surgery for treatment of anal fistula is largely dependent on the type of surgery as well as its complexity. The position of the fistula also plays a role.

Usually, the specialist recommends guidelines to be followed during post-operative care. In most of the cases post-surgery, the wound heals within 6 weeks.

Some of the post-operative guidelines are as follows :

• For pain relief, patients can take over-the counter pain relievers. Ibuprofen or Paracetamol is adequate
• Any pain during bowel movements should not be ignored and needs medical attention
• Clean the wound by washing it many times during the day. Take care to softly  pat it dry and no force or rubbing is advisable on the operated area. Sometimes discharge can leak and can spoil the clothes. An extra gauze cover may be used to protect
• The wound dressing needs to be changed regularly
• For first few weeks after the surgery, avoid sexual intercourse
• Gentle exercise is recommended so that there is no pressure on the healing process

Are there any side effects after the treatment for anal fistula?

Patients that have undergone treatment for anal fistula may experience the following side effects, which may disappear in few days once the healing process kick starts.

• Site of the wound may feel sore
• Diarrhoea
• Constipation
• Cramping
• Nausea

Any severe pain while passing motion or a bowel movement should be reported.

Can anal fistula be prevented?

The main cause of anal fistula is the formation of abscesses. Although there is very little one can do to prevent an anal fistula, there are certain steps that can be followed to prevent the formation of abscesses in the anorectal area.

• Maintain good hygiene and cleanliness in the anal region
• Do not clean the anal region excessively
• Consume a high fibre diet with plenty of fruits and vegetables
• Adopt a habit of regular bowel movements to prevent  constipation

How to ensure emotional well-being for those undergoing treatment for anal fistula?

It is not easy for anyone living with an anal fistula. The entire process right from diagnosis to recovery is gradual and this can be quite frustrating. The condition can negatively affect a person’s quality of life. It may be heartening to know that fistula surgery is mostly successful. Further, the rates of recurrence of anal fistulas are relatively low.  There are many surgical treatment options for this condition. The positive aspect is, this condition is not permanent.

People going through this condition can get a lot of support from others with similar experiences.

Best treatment options for anal fistula

Treatment for anal fistula is done in two ways. It can be treated with open surgery or using laser technique.

Anal fistulas heal well after surgery, and it is, therefore, the go-to treatment for this medical condition.  A number of hospitals, nursing homes and clinics offer surgeries for anal fistula.

Further, hospitals offering surgery for anal fistula are well equipped with the latest technology and tools that help deliver best care to patients. Medical surgeons treating fistula are highly experienced and can effectively manage any complications related to the fistula.  Patients can avail the best treatment without worrying about medical bills.

Hospitals offer complete treatment right from consultation to prepare for surgery and post-operative care. Patients approaching hospitals for advice get the following:

• Patient profiling or getting the complete medical history of the patient
• Selecting experienced specialist and slotting the appointment for consultation
• Discussing current trends in treatment of anal fistula with the best form of treatment  
• Facilitating   medical insurance if any
• Enabling post-surgery care to expedite healing
• Enabling consultation on diet and nutrition
• Tips to prevent fistulas from recurring

References