BCG into the bladder

BCG stands for Bacillus Calmette-Guerin. It's a vaccine which is a type of immunotherapy medicine. 

You usually have BCG into the bladder if you have a high risk of non muscle invasive bladder cancer coming back or spreading into the deeper layers of your bladder.

What is BCG?

BCG is a vaccine for tuberculosis (TB). It is also helps to stop or delay bladder cancers growing back or spreading into the deeper layers of the bladder.

The vaccine contains a weakened bacteria that can be used as a medicine.

We are not quite sure how BCG works for bladder cancer. It seems to encourage cells of the immune system to grow and become very active in the bladder lining. These cells probably kill off any cancer cells that might grow back or have been left behind. This is called immunotherapy.

BCG helps to stop bladder cancers coming back in many people.

When do you have it

Your treatment plan depends on your risk of the bladder cancer spreading or coming back after treatment. Your doctor will tell you whether you have:

  • low risk non muscle invasive bladder cancer
  • intermediate risk non muscle invasive bladder cancer
  • high risk non muscle invasive bladder cancer

You usually have BCG into the bladder if you have:

  • a high risk of non muscle invasive bladder cancer coming back or spreading into the deeper layers of your bladder

You have a course of BCG after surgery to remove the bladder tumours (TURBT). 

You usually have BCG into the bladder once a week for 6 weeks. This is called the induction course.

You may then have BCG into the bladder every few weeks or months for the next 1 to 3 years. This is called maintenance BCG therapy.

For intermediate risk non muscle invasive bladder cancer

You might have BCG if you can't continue with chemotherapy into your bladder because of side effects. Or, if your tumours come back during the course of chemotherapy.

What happens

Where you have BCG

You usually have treatment at the cancer day clinic.

Before you start BCG

Before each treatment, you need to stop drinking fluids. This stops the urine from diluting the drug in your bladder and will help you hold the BCG more easily. Your hospital will tell you when to stop drinking. 

On the day a nurse will check your urine to see if you have any infection. You also see the doctor. 

How you have BCG into the bladder

You have the BCG into your bladder through a thin tube (catheter). The catheter goes into your bladder through the urethra. The urethra is the tube that carries wee (urine) from the bladder out of the body. The doctor or nurse puts in the catheter on the day unit.

BCG is a liquid. Your doctor or nurse puts the liquid into your bladder through the catheter. Usually, they then remove the catheter.

Diagram showing how you have drug treatment into the bladder

You must not pass urine for 2 hours. This gives the BCG time to be in contact with the lining of the bladder. Some hospitals may ask you to change position every now and again to make sure the drug reaches all parts of your bladder lining.

When you do pass urine, you need to be careful for 6 hours after the treatment because the vaccine contains bacteria. Your nurse or doctor will ask you to:

  • be careful when you pass urine so that you don't get it on your skin - men should sit down to pass urine, to reduce the chance of splashing
  • pour about half a pint of neat bleach into the toilet bowl after you've been to the toilet, and leave it for 15 minutes before flushing
  • wash your hands and genitals immediately with warm soapy water after you pass urine

When you go home

Some hospitals allow you to go home with the medicine in your bladder if you live close by and are okay with the treatment. Your team will let you know if you can do this. You should follow the advice on what to do when you pass urine.

You need to drink lots of fluid (2-3 litres) after this treatment for 24 hours. It helps clear your system of the BCG.

You should not have sex for 24 hours after each treatment. During your course of treatment and for a week afterwards, you should wear a condom during sex.

Having bladder cancer and its treatment can be difficult to cope with. Tell your doctor or nurse about any problems or side effects that you have. The nurse will give you telephone numbers to call if you have any problems at home.

Possible side effects

You might get some side effects with this treatment. These might include:​​

  • having an irritated bladder, which feels a bit like having a urine infection
  • passing urine more often and more urgently than usual
  • having blood or debris in your urine
  • flu-like symptoms for 24 to 48 hours after each treatment
  • discomfort and pain when passing urine

If you have any of these symptoms, tell your doctor or specialist nurse. They might be able to help ease and treat these side effects.

Rare side effect

There is a very small chance that some of the BCG could get into your system. This causes an infection similar to TB, which needs treatment. This rare side effect could happen during or some months after treatment.

Some of the general symptoms are:​

  • fever and chills
  • joint or muscle pain
  • feeling sick or vomiting
  • cough
  • skin rash
  • feeling extremely tired

You might have other symptoms depending on where the infection causes problems in your body. For example, an infection in your lungs might cause breathlessness.

Contact your doctor immediately if you have any of these symptoms or have a high temperature for more than 48 hours. Do not wait until your next appointment. Tell your doctor you've had BCG treatment if they don’t already know.
  • Instillation Of BCG Into The Bladder For Immunotherapy. Information about your procedure from the British Association of Urological Surgeons (BAUS)
    British Association of Urological Surgeons, 2017

  • Electronic medicines compendium
    Accessed October 2022

  • Guidelines on Non-muscle-invasive Bladder Cancer (Ta, T1 and CIS)
    M Babjuk and others
    European Association of Urology, 2022

  • Society for Immunotherapy of Cancer consensus statement on Immunotherapy for the treatment of bladder carcinoma
    A M Kamat and others
    Journal of ImmunoTherapy of Cancer, 2017. Volume 5, Page 68

  • Managing the adverse events of intravesical bacillus Calmette-Guérn therapy
    K Decaestecker and W Oosterlinck
    Research and Reports in Urology, 2015. Volume 7, Pages 157 - 163

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information.. 


Last reviewed: 
19 Oct 2022
Next review due: 
19 Oct 2025

Related links