A fistula is an abnormal opening between organs or other structures in the body. Fistulas are more common in the pelvic area but can happen in different parts of the body.

They are a rare side effect of cancer treatment. Less commonly, they develop because of the cancer growing.

The symptoms depend on where it is in the body. You may get urinary and bowel symptoms if the fistula is in the pelvis. A fistula between the bladder and vagina may cause urine to leak through the vagina.

You usually need a scan to diagnose it. Treatment will depend on the cause and the part of the body affected. Surgery can sometimes be used to repair a fistula or help with the symptoms. Fistulas between the gullet and windpipe or airway may be treated with a small tube called a stent.

But it’s more common to manage a fistula by controlling the symptoms. Some fistulas may take a long time to heal and may not heal completely. Your cancer nurse or doctor will support you and explain what can be done.

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.

A fistula can be difficult to cope with. The symptoms may sometimes involve body fluids leaking into other areas of the body. Your specialist nurse and doctor will explain the best ways to treat or manage the symptoms of the fistula.

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 in the area (especially the pelvis) on their own or together. Radiotherapy and chemotherapy together (chemoradiation) may also increase risk.
  • You have a long-term side effect of pelvic radiotherapy called chronic radiation enteritis.
  • 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®).
  • You have certain medical conditions. For example, high blood pressure, anaemia, diabetes, bowel conditions such as colitis, Crohn’s disease or diverticulitis, or being very overweight.

Signs and symptoms of a fistula

The symptoms will depend on the parts of the body that are affected. In this information, we’ve listed the most common symptoms that may be a sign of a fistula.

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

Urinary symptoms

Depending on the type of fistula, you may have different urinary symptoms.

Symptom of a fistula between the ureter and vagina or between the bladder and vagina:

  • leaking urine through the vagina.

Symptoms of a fistula between the bowel and bladder:

  • pain passing urine
  • passing urine more often
  • urine that is smelly and looks cloudy or muddy in colour.

Symptom of a fistula between the bowel and ureter or between the bowel and bladder:

  • Leaking urine from the back passage.

Bowel symptoms

Symptom of a fistula between part of the bowel and the vagina:

  • Passing wind and poo (bowel motions) through the vagina.

Symptom of a fistula affecting any part of the bowel:

  • Diarrhoea – but this is a common symptom of many other conditions.

Vaginal and vulval symptoms

Symptoms of a fistula joining the vagina and bowel:

  • vaginal discharge that smells unpleasant
  • redness and soreness of the vagina (vaginitis)
  • redness and soreness of the skin in the vulva.

Chest symptoms

Symptoms of a fistula joining the gullet (oesophagus) and the windpipe (trachea) or airways:

  • coughing after eating
  • feeling short of breath
  • having chest infections.

Diagnosing a fistula

You may need different tests to find out the exact cause of your symptoms. The symptoms of a cancer fistula may be similar to those of some other medical conditions.

It’s 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 talk to you about previous cancer treatment. They will do a physical examination of the affected area. If the fistula is in the pelvic area, you may feel embarrassed or nervous about this. If you would prefer to be examined by a doctor of the same sex as you, let your doctor or nurse know.

The tests you have will depend on your symptoms and the part of your body that is affected. Your doctor or nurse will explain them to you and answer any questions you have. Some of the tests that may be used 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 10–15 minutes. Blue staining on the tampon means there is a fistula.

CT (computerised tomography) scan

A CT scan takes a series of x-rays that create a three-dimensional (3D) picture of the inside of your body. It can be used to find a fistula and show exactly which parts of the body are affected.

The scan is painless and takes about 10–30 minutes. CT scans use a small amount of radiation, which will be very unlikely to harm you and will not harm anyone you come into contact with. You may be asked not to eat or drink for at least four hours before the scan.

MRI (magnetic resonance imaging) scan

This test is similar to a CT scan, but uses magnetism instead of x-rays to create a detailed picture of an area of your body. During the scan you will be asked to lie very still on the couch inside a long tube for about 30 minutes. It is painless but can be uncomfortable, and some people can feel a bit claustrophobic during the scan. It is noisy, but you will be given ear plugs or headphones.

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.

There are different types of contrast x-ray:


To 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.


This test can help to show whether there is a fistula involving the vagina. A thin tube (catheter), which has a small balloon on the end, is inserted 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.


For this test, 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. 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.

A dye is injected into a vein, usually in your arm, and flows through your bloodstream to your kidneys. The doctor can watch the flow of the dye on an x-ray screen and see any abnormalities in the kidneys, bladder and the rest of your urinary system.

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

Examination under anaesthetic (EUA)

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 for the fistula will often 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 anti-cancer treatments, such as chemotherapy, may be given to shrink the tumour. Your doctor and nurse specialist will talk to you about treatments to help manage the symptoms.

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

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
  • 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.

Fistulas can take many weeks or months to heal. Unfortunately, some fistulas may never heal, but it is often possible to control the symptoms successfully. Your doctor or specialist nurse can discuss treatment options with you. If you are worried about your symptoms at any time, contact your doctor or specialist nurse for advice.


Surgery may only be possible if the tissue in the area around the fistula is healthy. Previous radiotherapy treatment to the area or scarring from previous surgery can affect healing. In these situations it may take longer to heal and sometimes it may not heal.

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 divert 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 be helpful.

If the fistula involves the urinary system, you may need a 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 (the donor site) and uses it to repair the fistula. The plastic surgeon will explain what your operation involves and answer your questions.


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.

Anti-cancer treatments

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 up.

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

You may have different treatments to help control the symptoms. It’s 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.

Skin care

Your skin may become sore and red, and can sometimes become infected and ulcerated. Using barrier films or creams that cover the area can help reduce symptoms. Some creams and films contain local anaesthetic, which helps reduce pain and discomfort.

Your specialist nurse can advise you on the best cream to use. They can also prescribe creams if necessary. It‘s 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. Don’t rub the area. If patting the area is too painful, try using a cool hairdryer or electric fan to dry the area. If your skin becomes infected, your doctor will prescribe anti-biotics, either as tablets or as a cream.

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 will be able to 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 prescribe drugs called somatostatin analogues, such as octreotide, along with fluid replacement to slow down the amount of fluid that is lost. They help increase the amount of fluid and nutrients absorbed in the bowel. Somatostatin analogues are given by injection under the skin (subcutaneously) or into a vein (intravenously).

Your doctor may prescribe other medicines such as loperamide and codeine phosphate. These drugs 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 aren’t 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.

Continence advice

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.

If you need to go to the toilet more often, or feel that you can’t 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 allows you to use their toilets, without them asking awkward questions. You can get the cards from the Bladder and Bowel Foundation for a small fee.

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

Pain control

You may have pain or soreness due to broken, sore or infected skin. Tell your doctor or nurse about this. They can prescribe effective painkillers and anaesthetic creams that can help relieve your symptoms.

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.

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 number of bacteria in the wound and control the smell. Charcoal dressings can help filter any smell.

If the fistula is infected, anti-biotics can help control it. Applying anti-biotic 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 with family and friends.

Your feelings

You may feel anxious, embarrassed or depressed because of your fistula. Many people feel isolated and worry about going out. If your fistula affects your appearance or has an unpleasant smell, you may be worried or embarrassed. It may affect how you see, feel and think about your body (body image). But remember that you will probably be much more aware of the fistula than other people.

Your family and close friends can also offer you support. You may also find it helpful to talk to your doctor or nurse about how you’re feeling. Support groups, counselling and complementary therapies such as relaxation and aromatherapy can also be helpful. Our cancer support specialists can give you details of support organisations and counselling services in your area.

If your fistula is affecting your relationships, The College of Sexual and Relationship Therapists may also be able to help.