Anal Fistula

An anal fistula is an abnormal opening between the external skin of the buttocks and the anal canal. It occurs in around 30-40% of patients with an anal abscess.

An anal fistula develops when an anal abscess bursts before it is treated or is not completely cured. An anal abscess is a painful pus-filled lesion caused by a bacterial infection in the tissues surrounding the anus.

Most anal abscesses are due to an infection in the internal glands of the anus. Moreover, anal conditions cause 80% of anal fistulas.


A anal fistula can be categorized into the following types depending on its location:

  • A Suprasphincteric Fistula
  • Transphincteric Fistula, or Horseshow Fistula
  • An Intersphincteric Fistula
  • An Extrasphincteric Fistula


An anal fistula can cause the following symptoms:

  • Irritation of the skin surrounding the anus
  • Excruciating pain while sitting, moving and passing stool
  • An unpleasant discharge from the anus
  • Pus or blood in the poop
  • Swelling and redness around the anus, as well as fever if you have an abscess.
  • Controlling bowel movements may be difficult in some instances.

The end of the fistula may be visible as a hole in the skin around the anus; however, patients may be unable to see it.

When to see a doctor?

If there are persistent symptoms of an anal fistula, talk to the primary healthcare provider immediately. Suppose the doctor thinks you might have a fistula. In that case, they can refer you to a specialist for further tests to confirm the diagnosis and determine the most suitable treatment.


One of the most common causes of anal fistula is an anal abscess that fails to heal completely even after the absence of pus. Other factors include:

  • Crohn’s Disease causes inflammation of the intestines and is the main cause of anal fistula.
  • Diverticulitis is another cause of anal fistula. It is swelling and infection in one or more diverticula that leads to fever, nausea, etc.
  • Hidradenitis Suppurativa is a skin condition that leads to scarring and abscesses. It leads to the formation of an anal abscess.

Risk factors

If an anal abscess develops, the chance of anal fistula formation. The following are some risk factors for developing an anal fistula:


Here are some tips to help you avoid an anal fistula:

Consuming a high-fiber diet

The best way to avoid hard bowel motions is to eat enough fiber-rich foods. Fiber-rich foods include:

  • Oatmeal, whole grains, and brown rice
  • Lentils and beans
  • Brussel sprouts and vegetables
  • Bananas, apples, pears, and berries are examples of fruits.

Drink sufficient water

Water and a fiber-rich diet are important for treating any anorectal ailment. Drinking enough water prevents constipation and hard stools, reducing the need to strain while passing a bowel movement. Drinking plenty of water throughout the day is important to avoid anal fistula. It will also help in the proper functioning of the digestive system.

Maintain cleanliness and dryness in your anal region

Anal fistulas are usually triggered by clogs and blockages in the anal canal. An anal fistula forms due to accumulated dirt and debris over time. To avoid this, wiping the anal region after each bowel movement is important. After cleaning, don't keep the area wet; pat it dry to prevent germs and infection.

Don’t strain while passing stool

Do not strain while passing stools. Straining may increase the anal skin's problems and lead the fistula to worsen. It is also important to prevent spending long periods sitting on the toilet seat. The longer you sit on the toilet seat, the more likely you strain and exacerbate the bowel motions.

Regular exercises

Almost all anorectal diseases are directly related to physical activities and how you keep the body active. Being physically active keeps the intestine active and functioning normally. Any action that creates tension or pressure on the abdomen should be avoided. Do not exercise with heavy weights. Do not sit in one position for prolonged periods. Regularly engage in moderate physical activities.


The anal fistula diagnosis include:

Physical Examination

The doctors perform a physical exam to identify the opening of the fistula, pain, and pus draining from the anal area. The doctor uses gentle pressing around the fistula to determine the bloody discharge and pain. While finding the external opening of an anal fistula is simple, finding the internal space of a fistula can be difficult.
A doctor performs a rectal examination by inserting a finger into the anus while wearing a glove and using a lubricating gel to determine the following:

  • Fistula extension
  • Sphincter muscles functioning
  • Area of infection

Other diagnostic tests are:


Proctoscopy is the use of a specialized telescope equipped with a fistula probe to look within the rectum. Proctoscopy is often conducted under general anesthesia.

Anal Endosonography or Anal Ultrasound

Anal Endosonography, often known as anal ultrasound test uses high-frequency sound waves to capture pictures beneath the surface of the anal canal.

Don’t strain while passing stool

Do not strain while passing stools. Straining may increase the anal skin's problems and lead the fistula to worsen. It is also important to prevent spending long periods sitting on the toilet seat. The longer you sit on the toilet seat, the more likely you strain and exacerbate the bowel motions.

MRI or Magnetic Resonance Imaging Scan:

MRIor Magnetic Resonance Imaging Scan: The Magnetic Resonance Imaging Scan technique uses strong magnetic and radio waves to create detailed pictures of the organs. This procedure is typically used for recurring or complex fistulae.

CT or Computerized Tomography Scan:

CT or Computerized Tomography Scan: The CT or Computerized Tomography Scan technique incorporates X-Rays, and computers can create detailed cross-sectional body pictures. This approach also helps in accurately detecting the level of inflammation.


The strength and complexities of the sphincter muscles are used to treat anal fistulas. However, no medications are available to treat this condition; the following surgical procedures must be performed:


This is the most common and effective surgical operation used to drain and open an anal fistula.

Seton Techniques

This procedure involves inserting the surgical thread into the fistula tract, allowing it to entirely drain and heal.

Advancement Flap Procedure

If the fistula passes through the anal sphincter muscles, this procedure is used to cover the hole and allow the fistula to heal.

Fibrin Glue of Collagen Plug

This is a non-surgical method in which the surgeon injects a special glue while under general anesthesia. This results in the fistula being closed and initiates the process of healing.

Do’s and Don’ts

The bowel movements are related to food intake. The doctor will always advise patients to adjust their diet if they have gastrointestinal diseases or conditions such as piles, fistula, fissures, etc. This aids in the relief of symptoms as well as the facilitation of smooth bowel motions.

What's more essential is to avoid foods that may aggravate the illness. The concern with anal fistula may reoccur with minor dietary and lifestyle changes. Following a good diet and healthy lifestyle practices ensure that the rectal fistula heals faster.

Do’s Don’ts
Wear a pad over the anal area until healing is complete. Take any over-the-counter medicines without consulting the doctor.
Avoid spicy and oily foods, Eat salty foods
Eat a diet high in fiber and drink plenty of fluids. Drink caffeinated beverages
Use a stool softener if needed Eat bakery items such as pastries, foods made of refined flour, hydrogenated oils, etc.
Eat a balanced diet to maintain bowel movements. Use harsh soaps in the affected region.

Apart from these dos and don’ts, one should eat on time, avoid big meals, and drink enough water. However, if the problem persists with severe pain or discomfort, visit your doctor for the finest fistula therapy.

Anal Fistula Care at Medicover

At Medicover hospitals, we have the best team of general surgeons and other specialists who treat anal fistula and its severe symptoms. Our highly trained doctors use the most up-to-date diagnostic tools and procedures to perform various medical tests, and treat patients. Our medical experts collaborate closely with patients to evaluate their health and treatment progress to achieve a faster and more lasting recovery.


Make an appointment just in few minutes - Call Us Now

Frequently Asked Questions

1. What is an anal fistula?

An anal fistula is an abnormal tunnel-like passage that forms between the inside of the skin around the anus, often known as the rectum. It typically develops as a result of an infection or abscess near the anus.

2. What causes an anal fistula?

Most anal fistulas come on by infections that start inside the anal gland, which then leads to an abscess. The abscess can cause tissue to break down, creating a pathway for the fistula to develop.

3. What are the common symptoms of an anal fistula?

Anal fistula symptoms may include discomfort, swelling, redness, discharge of pus or blood, itching, and discomfort while sitting or during bowel movements.

4. How is an anal fistula diagnosed?

Normally, a doctor will do a physical examination of the affected area to diagnose an anal fistula. Sometimes, additional tests like an MRI or a fistulogram may be recommended to assess the extent and location of the fistula.

5. Is surgery the only treatment option for anal fistulas?

Surgery is often the main treatment for anal fistulas, especially when they are causing symptoms. Surgery aims to remove the fistula and any associated abscess or infection. In some cases, a seton (a small piece of surgical thread) may be placed to help drain the fistula and prevent recurrence.

6. What is the recovery process after anal fistula surgery?

Recovery after anal fistula surgery can vary, but it generally involves keeping the area clean, taking prescribed medications, and avoiding activities that might strain the surgical site. Follow your doctor's post-operative instructions closely for the best outcome.

7. Can anal fistulas recur after surgery?

Yes, there is a possibility of recurrence. However, with proper surgical techniques and follow-up care, the risk of recurrence can be minimized.

8. Are there non-surgical treatments for anal fistulas?

Non-surgical treatments such as antibiotics and sitz baths can sometimes help manage symptoms, but they may not fully cure the fistula.

9. Can anal fistulas cause complications?

Yes, if left untreated, anal fistulas can lead to complications such as chronic pain, recurrent infections, and abscesses. It's important to seek medical attention if you suspect you have an anal fistula.

10. When should I see a doctor for an anal fistula?

If you experience persistent pain, swelling, discharge, or discomfort around the anus, it's recommended to consult a medical professional. Early diagnosis and treatment can prevent complications and improve your quality of life.