A fistula is an abnormal opening between two parts of the body or a part of the body and the skin. It is a rare side effect of cancer treatment. Less commonly, they develop because of the cancer growing.

What is a fistula?

A fistula is an abnormal opening that connects two or more organs or spaces inside or outside the body. For example, a fistula can develop between the bowel and the bladder, or between the bowel and the skin.

Cancer fistulas are rare. They are more common in the pelvic area (lower tummy between your hips) but can develop in other parts of the body.

They can be caused by cancer treatment, and may take many months or years to develop. Less commonly, they are caused by cancer growing into an area of the body. Some conditions or treatments unrelated to cancer can also cause a fistula.

Illustration of a fistula in a woman's body

Illustration of a fistula in a woman's body

Illustration of a fistula in a man's body

Illustration of a fistula in a man's body


Causes and risk factors of a cancer fistula

Certain risk factors may increase the chance of developing a fistula. But having some or all of these risk factors does not mean you will develop a fistula. Most people with cancer never develop a fistula.

The risk of getting a cancer fistula may increase if:

  • the cancer started in the pelvic area, for example cervical cancer or bowel cancer
  • the cancer is large and grows quickly (high-grade cancer)
  • you have had surgery or radiotherapy (on their own or together) in the same area of the body, especially the pelvic area
  • you have had radiotherapy and chemotherapy together (chemoradiation)
  • you have a long-term side effect of pelvic radiotherapy called pelvic radiation disease
  • you have had a biopsy (sample of tissue taken for testing) from an area where you previously had radiotherapy
  • you have had previous treatment with certain targeted therapy drugs, for example bevacizumab (Avastin®) and pazopanib (Votrient®).

The risk may also increase if you have other conditions. These could include being very overweight or having high blood pressure, anaemia or diabetes. Other possible risk factors are bowel conditions such as colitis, Crohn’s disease or diverticulitis.

Signs and symptoms of a fistula

The signs and symptoms will depend on the parts of the body that are affected.

Most of these symptoms can be caused by more common conditions. But it is important to get them checked by your doctor.

Symptoms of a fistula include the following:

Urinary symptoms

  • Pain while passing urine (peeing).
  • Smelly and cloudy urine, or urine that is muddy in colour.
  • Passing urine more often.
  • Passing wind or stools (poo) in urine.

These symptoms could indicate a fistula between the bowel and bladder.

Bowel symptoms

  • Diarrhoea (this is also a common symptom of many other conditions).
  • Leaking urine (pee) from the back passage.

These symptoms could indicate a fistula between the bowel and ureter or between the bowel and bladder.

Vaginal and vulval symptoms

  • Vaginal discharge that smells unpleasant.
  • Redness and soreness of the vagina (vaginitis), or redness and soreness of the skin in the vulva.
  • Leaking urine through the vagina.
  • Passing wind or stools through the vagina.

These symptoms could indicate a fistula between the vagina and the bowel, between the ureter and the vagina or between the bladder and the vagina.

Chest symptoms

  • Coughing after eating.
  • Feeling short of breath.
  • Having chest infections.

These symptoms could indicate a fistula between the gullet (oesophagus) and the windpipe (trachea) or airways.

Diagnosing a fistula

You may have tests to diagnose a fistula. The tests you have will depend on your symptoms and the part of your body that is affected. It is important to know whether a fistula has developed because of previous treatment, or as a result of the cancer growing. The way a fistula is managed may depend on why it developed.

Your doctor will ask about your symptoms and previous cancer treatment. They will also do a physical examination of the affected area. If you would prefer to be examined by a doctor of the same sex as you, let your doctor or nurse know.

You may have a CT scan or an MRI scan.

Other tests you may have are:

Methylene blue test

This is used to help diagnose a fistula between the vagina and bowel. A tampon is placed into the vagina and then some harmless blue dye (methylene) is placed into the back passage. The tampon is removed after about 10 to 15 minutes. Blue staining on the tampon means there is a fistula.

Contrast x-rays

Sometimes a liquid that shows up on x-rays is used to help show the parts of the body affected by the fistula. The liquid is called a contrast medium. It can be injected into a vein in your arm or put into the part of the body that is affected, such as the bladder, the vagina or a fistula opening on the skin. The liquid is completely harmless.

The contrast may make you feel hot and flushed for a few minutes, but this feeling gradually disappears. You may feel some discomfort, but only be for a short time. You should be able to go home as soon as the test is over

There are different types of contrast x-ray:

  • Cystography 

    This test can help diagnose a fistula involving the bladder. The contrast liquid is put into the bladder using a thin tube (catheter). You then have x-rays taken. Any leakage of the liquid from the bladder will show the position and size of a fistula.

  • Vaginography

    This test can help to show whether there is a fistula involving the vagina. A doctor inserts a thin tube (catheter), which has a small balloon on the end, into the vagina. The balloon is then inflated to block the opening of the vagina. The contrast liquid is injected into the vagina through the catheter. X-rays of the vagina are taken, and any leakage of the liquid will show the position and size of a fistula.

  • Fistulography

    You may have this test if you have a fistula opening onto the skin. The doctor inserts a very small catheter or blunt needle is inserted into the opening of the fistula on your skin. The contrast liquid is then injected into the fistula and x-rays are taken.

  • Intravenous urogram (IVU/IVP)

    This test is also called an intravenous pyelogram. A dye is injected into a vein, usually in your arm, and flows through your bloodstream to your kidneys. It can help show a fistula involving the bladder and kidneys. It is done in the hospital x-ray department and takes about an hour. The doctor can watch the flow of the dye on an x-ray screen and see any abnormalities.

Examination under anaesthetic

This allows your doctor to carefully examine the areas affected by the fistula while you are under a general anaesthetic. The doctor can do a thorough examination without causing you any discomfort.

Treating a cancer fistula

The treatment you have will depend on its cause and how well you are.

If the tissues in the area around the fistula are healthy, surgery to close the fistula may be possible. If the fistula is due to the cancer coming back, it may not be possible to have surgery. Other treatments, such as chemotherapy, may be given to shrink the tumour.

You may be seen by a number of different doctors. For example:

  • if you have a fistula affecting your bowel and bladder, you may see a bowel specialist (gastroenterologist), a bowel surgeon and a bladder specialist (urologist)
  • if you have a fistula involving your bladder and vagina, you may see a gynaecologist and a bladder specialist.

Some people may also see a plastic surgeon.

Some fistulas will close without surgery or other cancer treatments. Fistulas can take many weeks or months to heal, while unfortunately others may never heal. In these situations, it is often possible to control the symptoms successfully. We have more information about this below.


The type of operation your specialist may suggest will depend on the areas of your body affected. Your team of specialists will discuss with you what the surgery will involve. They will explain and discuss with you how the operation will affect you and whether there are any possible risks.

Surgery to create a stoma

If the fistula involves part of the bowel, you may need an operation to bring an opening of the bowel onto the skin of the tummy (abdomen). This is called a stoma. The stoma is called a colostomy if it uses part of the colon, and an ileostomy if it uses the small bowel. A bag is worn over the stoma to collect bowel motions.

The stoma will be either temporary or permanent. You may have a temporary stoma to rest the bowel. This allows symptoms, such as infection and inflammation, to improve before an operation to repair the fistula. It can also allow the area to heal after surgery.

Your surgeon and specialist nurse will talk to you about having a stoma if they think it would help. We have more information on stomas.

If the fistula involves the urinary system, you may need a stoma for urine to leave the body through. You will wear a bag over the stoma to collect urine. This is called a urostomy. The urostomy may be temporary or permanent.

Plastic surgery

Plastic surgery usually involves a tissue flap. A tissue flap uses tissue and skin from a different part of the body to repair the fistula. The plastic surgeon will explain what your operation involves and answer any questions you may have.


A small tube called a stent can be used to seal a fistula between the windpipe (trachea) and the gullet (oesophagus). You usually have a stent put in under a general anaesthetic. It can be placed in the gullet or in the windpipe or sometimes in both.

The doctor places the stent inside the gullet using an endoscope or inside the windpipe using a bronchoscope. A scope is a thin, flexible tube with a light and camera at the end. The stent is folded flat when it’s first inserted. As it comes out of the scope, it opens up like an umbrella. It pushes against the wall of the gullet or windpipe, sealing the hole from the fistula. The stent can stay in permanently.

You may see a chest (thoracic) surgeon for treatment. They will explain more about having a stent.

Chemotherapy and radiotherapy

If the fistula has developed because the cancer is growing, you may be given treatment to shrink the cancer. This may help the fistula close.

Depending on the type of cancer and the position of the fistula, chemotherapy and sometimes radiotherapy may be used. Your doctor or specialist nurse will explain the treatment and give you information about any possible side effects.

Controlling the symptoms of a cancer fistula

Sometimes a fistula will close without surgery or other cancer treatments. While it is healing, it can be managed with treatment to control symptoms.

Fistulas can take many weeks or months to heal. Unfortunately, some may never heal, but it is often still possible to successfully control the symptoms.

Your doctor or specialist nurse can discuss treatment options with you. You may have different treatments to help control the symptoms.

It is important to tell your nurse or doctor how the fistula is affecting you. They can give you advice on the best way to manage your symptoms.

Sore skin

Your skin may become sore and red, and can sometimes become infected and ulcerated. If your skin becomes infected and sore, your nurse or doctor can prescribe painkillers and anaesthetic creams that can help. Your doctor will also prescribe antibiotics, either as tablets or as a cream.

Using barrier films or creams that cover the area can help reduce symptoms.

It is important to keep the area as clean as possible to help prevent infection. The area should be washed gently. Your nurse can tell you which product to wash the area with. Many soaps and shower gels may cause irritation.

After washing, pat the area dry with a clean, soft towel. Do not rub the area. If patting the area is too painful, try using a cool hairdryer or electric fan to dry the area.

Leakage from the fistula

If the fistula opens on to your skin, fluid may leak out. Your nurse will give you advice on dressings you can use to cover the fistula. There are dressings that can absorb the leakage and help you feel more comfortable.

If there is a large amount of leakage, they may suggest using a drainage bag. The bag is stuck on to the skin, over the area where the fistula opens on to the skin.

Your doctor, specialist nurse or community nurse will be able to advise you on the best way to manage any leakage from your fistula. You or your carers can be taught how to change the dressings or manage the drainage bag. If you are at home and need help with this, a district nurse will be able to visit you and provide support.

Unpleasant smell

Sometimes a fistula can smell unpleasant. Many people find this symptom the most distressing.

Your nurse may use different dressings to help control an unpleasant smell. Some contain silver, which can reduce the bacteria in the wound and control the smell. Charcoal dressings can help filter any smell.

If the fistula is infected, antibiotics can help control it. Applying antibiotic gels directly on to the area can also help. Your doctor or nurse will be able to tell you more about this.

You may feel self-conscious about an unpleasant smell, particularly when you are with other people. Air fresheners, environmental air filters and aromatherapy oils may disguise unpleasant smells and can help you feel more comfortable.

Losing fluid

If a fistula is affecting the bowel, especially the small bowel, you may lose a lot of fluid. This can lead to dehydration and affect the balance of nutrients in your body.

You will be encouraged to drink plenty of liquids. Your cancer doctor or nurse can tell you how much you should drink each day. Sometimes you may be given fluids by a drip (infusion) into a vein (intravenously).

Doctors sometimes also prescribe drugs to help. Drugs such as octreotide slow down the amount of fluid that is lost. Octreotide is given by injection under the skin (subcutaneously) or into a vein (intravenously).

Other medicines such as loperamide and codeine phosphate can slow down the bowel and reduce the amount of fluid lost.

If you are losing a lot of fluid from the bowel, especially the small bowel, you may not be getting enough nutrients to keep your body healthy. A dietitian can give you advice about the best way to stay well nourished while slowing down the amount of leakage.

Your dietitian can advise you if a low-fibre diet would be helpful.

If you are not getting enough nutrients and are losing weight, you may need fluids containing nutrients. You have these through a drip into a vein. This is called parenteral nutrition.

Bladder and bowel problems

If you need to go to the toilet more often, or feel that you cannot wait when you do want to go, you can get a card to show to staff in shops, restaurants and pubs. The Just Can’t Wait toilet card from the Bladder and Bowel Community allows you to use their toilets, without them asking awkward questions.

Macmillan also has a free toilet card that can help you access toilets when you are away from home.

If you are having problems with abnormal leakage of urine or loose bowel motions, it can be distressing and embarrassing. Your nurse can give you advice about incontinence pads and aids. They can also give you emotional support. You can ask to be referred to a continence adviser or a stoma nurse. The Bladder and Bowel Foundation may also be able to help. They provide information and support for people affected by bladder or bowel problems.

Diarrhoea or constipation

If you have diarrhoea or are constipated, changing your diet may help. A dietitian or specialist nurse can give you further advice. Avoiding too much fibre and eating small meals made from light foods can often slow diarrhoea down. Anti-diarrhoea tablets can also help.

If you have constipation, increasing the amount of fluid you drink and eating a diet high in fibre can often help relieve it. Laxatives, and sometimes enemas, may also be needed.

Your doctor or nurse will give you more advice.

Your feelings about having a fistula

You may feel anxious, embarrassed or depressed because of your fistula. The fistula may affect how you see, feel and think about your body (body image). Talking to family or friends often helps. You may also find it helpful to talk to your doctor or nurse about how you are feeling. They can refer you to local counselling services.