Fistulas and cancer
What is a fistula?
Fistulas may be caused by injury, infection or inflammation. Sometimes they can be caused by cancer treatment. Less commonly, a fistula can be caused by cancer growing into an area of the body.
Fistulas caused by cancer are rare and can take many months or years to develop. They can develop in the pelvic area (the lower area between the hips). For example, an opening may develop between:
- the bladder or bowel and the vagina
- the bowel and the bladder
- the rectum and the bladder or urethra.
Less often, cancer or cancer treatment can cause a fistula in other parts of the body, such as inside the chest. Or fistulas can develop inside the body and come out through the skin.
Having a fistula can be difficult to cope with physically and emotionally. Your specialist nurse and doctor can support you. They can explain the best ways to treat or manage fistula symptoms.
Fistula in male reproductive organs
Fistula in female reproductive organs
Causes of a fistula
Most people with cancer never develop a fistula. Certain risk factors may increase the chance of developing a fistula. But having some or all these risk factors does not mean it will happen.
The following factors may increase your risk of getting a fistula:
- The cancer started in the pelvic area – for example, if you were diagnosed with cervical cancer or bowel cancer.
- The cancer is large and grows quickly. This is called high grade cancer.
- You have had surgery or radiotherapy, or both. Radiotherapy and chemotherapy together (chemoradiation) may also increase the risk.
- You have late effects side effects after pelvic radiotherapy. This is sometimes called pelvic radiation disease (PRD).
- You have had a biopsy from an area where you previously had radiotherapy.
- You have had previous treatment with some targeted therapy drugs - for example bevacizumab (Avastin®) and pazopanib (Votrient®).
- You have other medical conditions such as colitis, Crohn’s disease or diverticulitis.
Signs and symptoms of a fistula
The symptoms depend on the parts of the body that are affected. In this information, we have listed the most common symptoms of some types of fistula.
Some of these symptoms can be caused by other conditions. But it is important to get them checked by your doctor.
Bladder symptoms
Symptoms of a fistula between the bowel and bladder include:
- pain when passing urine (peeing)
- passing urine more often
- bubbles in the urine (pee)
- urine that is smelly and looks cloudy or muddy in colour
- passing stools (poo) in urine.
Bowel symptoms
If a fistula is between the bowel and ureter or between the bowel and bladder, you may have urine leakage from the rectum (back passage).
If it affects any part of the bowel, you may have diarrhoea. But this is a common symptom of many other conditions.
Vaginal symptoms
If a fistula is between the ureter and vagina or between the bladder and vagina, you may have urine leakage through the vagina.
If a fistula joins the vagina and bowel, you may have the following symptoms:
- vaginal discharge that smells unpleasant
- passing wind and stools through the vagina
- soreness of the vagina (vaginitis)
- skin irritation and soreness around the vulva.
Chest symptoms
If a fistula joins the oesophagus (gullet) and the trachea (windpipe) or airways, you may have the following symptoms:
- coughing after eating or drinking
- feeling short of breath
- chest infections.
Diagnosing a fistula
A fistula can be caused by cancer treatment or the cancer itself. The doctor needs to know the cause to decide on the treatment.
Your doctor will ask about any cancer treatment you have had and about your symptoms. Depending on your symptoms, you may have some tests. If you have any worries about having an internal examination, tell the nurse or doctor.
You may also need an internal examination. An internal examination is a physical examination of the following:
- vulva
- vagina
- cervix
- uterus
- fallopian tubes
- ovaries
- rectum.
Your nurse or doctor can answer any questions you have and explain the ways they can make it easier for you.
Methylene blue test
This is used to help diagnose a fistula between the vagina and bowel. A tampon is placed into the vagina. Then some blue dye called methylene is placed into the rectum. The tampon is removed after about 10 to 15 minutes. Blue staining on the tampon means there is a fistula.
CT scan
A CT scan makes a detailed picture of the inside of the body. The picture is built up using x-rays taken by the CT scanner. It can be used to find a fistula.
Before the scan, you may be given a drink or an injection a special dye. This is called contrast. It can help show a fistula more clearly on the images.
MRI scan
Contrast x-rays
These are x-rays that use a special liquid dye called contrast. Contrast can help the doctor to see areas inside the body more clearly on an x-ray image. This can help to find a fistula, as the contrast will show the opening. Contrast x-rays have different names depending on the part of the body:
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Cystogram
Contrast is given into the bladder through a tube (catheter).
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Vaginogram
Contrast is given into the vagina through a tube (catheter).
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Fistulogram
Contrast is given through a small catheter or blunt needle into an opening in the skin to see where it goes.
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Intravenous urogram (IVU/IVP)
Contrast is injected into a vein, usually in the arm. It flows through the bloodstream to the kidneys. The doctor can watch the flow of the dye on an x-ray screen and see any abnormal areas in the kidneys, the bladder and the rest of the urinary system. The contrast 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. A spinal anaesthetic may also be used for a fistula within the pelvic area. The doctor can do a thorough examination without causing you any discomfort.
Treating a cancer fistula
The treatment you have for the fistula usually depends on what caused it and how well you are. Your doctor or specialist nurse can discuss treatment options with you.
If the tissues around the fistula are healthy, it may be possible to have surgery to close the fistula.
If the fistula is caused by the cancer coming back, it may not be possible to have surgery. You may have other treatments, such as chemotherapy, to shrink the tumour. Your doctor and specialist nurse 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, you may have treatment to control symptoms.
You may meet with different doctors depending on where the fistula is.
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If you have a fistula affecting your bowel, bladder or vagina
You may meet with a:
- gastroenterologist – a doctor who treats problems with the digestive system
- colorectal surgeon – a doctor who does operations (surgery) on the large bowel
- urologist – a doctor who treats problems with the kidneys, bladder and male reproductive system
- gynaecologist – a doctor who treats problems with the female reproductive system.
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If the fistula affects your skin
You may meet with a plastic surgeon. This is a doctor who does operations (surgery) to repair or reconstruct tissue and skin.
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If the fistula affects your chest
You may see a thoracic surgeon. This is a doctor who does operations on the chest.
Fistulas can take weeks or months to heal. Some fistulas may never heal. But it is often possible to control the symptoms. If you are worried about your symptoms at any time, contact your doctor or specialist nurse for advice.
Surgery
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 the healing. In these situations, it may take longer to heal and sometimes it may not heal.
The type of surgery depends on the areas of your body affected. Often the surgeon will use your own body tissue to repair the fistula.
Your specialist team can explain how surgery will affect you and the possible risks.
Surgery to create a stoma
If the fistula affects 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
- an ileostomy, if it uses the small bowel.
Having a stoma means stool will not pass out of the rectum and anus in the usual way. Instead, it will pass out of the stoma, into a disposable bag that is worn over the stoma.
The stoma will be either temporary or permanent. You may have a temporary stoma to:
- rest the bowel before fistula surgery and allow symptoms, such as infection and inflammation, to improve
- allow the area to heal after fistula surgery.
Or, you may have a stoma to help control your symptoms.
Your surgeon and specialist nurse will talk to you about having a stoma if they think it would help.
If the fistula involves the urinary system, you may need a stoma to pass urine. This is called a urostomy. The urostomy may be temporary or permanent.
Stents
A small tube called a stent can be used to seal a fistula between the trachea (windpipe) and the oesophagus. You usually have a stent put in under a general anaesthetic. It can be placed in the oesophagus or in the trachea, or sometimes in both.
The doctor places the stent inside the oesophagus using a tube called an endoscope, or inside the trachea 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 is first inserted. As it comes out of the scope, it opens up like an umbrella. It pushes against the wall of the oesophagus or trachea, sealing the hole created from the fistula. The stent can stay in permanently.
Cancer treatments
If the fistula has developed because the cancer is growing, you may have treatment to shrink the cancer. This may help the fistula to close. Treatment depends on the type of cancer and where the fistula is. You may have chemotherapy or radiotherapy treatment.
Coping with the symptoms of a cancer fistula
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.
Skin care
Your skin may become sore and irritated. It can sometimes become infected and ulcerated. If your skin is broken or sore, your doctor or nurse can prescribe painkillers and local anaesthetic creams to help. Use barrier films or creams to cover the affected area. This can help reduce symptoms. If your skin becomes infected, your doctor will prescribe antibiotic tablets or cream.
After washing, pat the affected skin dry with a clean, soft towel. Do not rub the area. If patting is too painful, try using a cool hairdryer or an electric fan to dry the area.
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 any unpleasant smell. Some dressings contain silver, which can reduce bacteria in the wound and control the smell. Charcoal dressings can also help manage any smell.
If the smell is caused by an infection, antibiotics can help. Antibiotic gels can also be applied directly onto the area. Your doctor or nurse can 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 help you feel more comfortable.
Leakage from the fistula
If the fistula opens on to your skin, fluid may leak out. Your nurse will give you advice about dressings you can use to cover the fistula. There are dressings that can absorb any leakage and help you feel more comfortable.
If there is a large amount of leakage, your nurse may suggest using a drainage bag. The bag is stuck over the area where the fistula opens onto the skin.
Your doctor, specialist nurse or community nurse can advise you on the best way to manage any leakage. They may teach you or your carers how to change the dressings or manage the drainage bag. If you are at home and need help with this, a district nurse can visit you and provide support.
Leakage from the bladder or bowel
Leakage of urine or stool can be distressing and embarrassing. Your nurse can give you advice about pads and aids. These can help you feel more confident and protect your clothes.
You can ask to be referred to a continence adviser or a stoma nurse. The Bladder and Bowel Community may also be able to help.
If you need to go to the toilet more often, you can get a card to show to staff in shops, restaurants and pubs. This will usually allow you to use their toilets, without awkward questions. Macmillan has a free toilet card. You can also get a similar free Just Can’t Wait toilet card from the Bladder and Bowel Community.
Fluid loss
If a fistula is affecting the bowel, especially the small bowel, your body may lose more fluids than you take in. This can cause dehydration, which affects your body functions.
Try to drink plenty of liquids. Your cancer doctor or nurse can tell you how much you should drink each day. Sometimes you may need an infusion (drip) of fluids into a vein (intravenously).
Your doctor may be able to give you something to help slow down the amount of fluid you are losing.
Medicines such as loperamide and codeine phosphate can slow down the bowel and reduce the amount of fluid lost.
Nutrition
If you are losing a lot of fluid from the bowel, especially the small bowel, you may not get enough nutrients to keep your body healthy. A dietitian can give you advice about the best way to stay well-nourished and slow 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 have fluids containing nutrients through a drip into a vein. This is called parenteral nutrition.
Your feelings
You may feel anxious, embarrassed or depressed because of your fistula. Or you may feel isolated and worry about going out. The fistula may affect how you see, feel and think about your body (body image). Talking to family or friends usually 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 for more support. Support groups and connecting with others who are going through the same experience can help. Some people find complementary therapies, such as relaxation and aromatherapy, helpful.
If the fistula is affecting your intimate relationships, organisations such as the College of Sexual and Relationship Therapists may be able to help.
Our cancer support specialists can give you details of support organisations and counselling services in your area. It may also help to share your experience with other people through Macmillan’s Online Community.
About our information
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.
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References
Below is a sample of the sources used in our late effects of pelvic radiotherapy information. If you would like more information about the sources we use, please contact us at informationproductionteam@macmillan.org.uk
M Iwamuro, K Hasegawa, Y Hanayama, H Kataoka et al. Enterovaginal and colovesical fistulas as late complications of pelvic radiotherapy Journal of General and Family Medicine. 2018 Jun 21. Available at https://pmc.ncbi.nlm.nih.gov/articles/PMC6119788/ [accessed March 2026]
S Haas, A Højer Mikkelsen, C Jensenius Skovhus Kronborg et al. Management of treatment-related sequelae following colorectal cancer. PubMed. Colorectal disease Journal. 15 August 2022. Available at https://pubmed.ncbi.nlm.nih.gov/35969031/ [accessed March 2026]
R Dalsania, K Shah, E Stotsky-Himelfarb, S Hoffe et al. Management of Long-Term Toxicity from Pelvic Radiation Therapy. Gastrointestinal cancer- Colorectal and anal. Ascopubs April 2021. Available at https://ascopubs.org/doi/pdf/10.1200/EDBK_323525 [accessed March 2026]
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