What to Expect: BCG Treatment

Before, During & After BCG: What to Expect

Last updated: January 2023

Bacillus Calmette-Guérin (BCG) is an immunotherapy used to treat bladder cancer. BCG treatment is made from a bacterium and is also used as a vaccine for tuberculosis.1,2 It is known as a “live” vaccine, which means it is a very weakened version of the original bacteria. BCG is placed in the bladder through a catheter and triggers the body’s immune system to stop or slow the growth of cancer cells. BCG causes inflammation in the bladder, which is a sign that the immune system is fighting off cancer.

BCG is a fairly non-invasive treatment; patients come into a doctor’s office to receive the treatment and are able to go home the same day. BCG is usually given once a week for 6 weeks following another common bladder cancer treatment: the transurethral resection of bladder tumor (TURBT) procedure. BCG can also be given as maintenance therapy over a period of up to 3 years.

Any new treatment or procedure can be confusing and scary. Knowing what to expect can hopefully help to reduce anxiety.


Your doctor will give you a set of instructions before your BCG treatment to help you prepare for the procedure.1 In general, patients are usually told to limit their fluid intake for 6 hours before treatment. Drinking less will ensure that less urine is produced, and this will prevent the BCG treatment from being diluted in the bladder. Patients may also be asked to pass urine right before the procedure to make sure the bladder is empty. You should be able to eat as you normally would before your BCG treatment but always check with your doctor for specific instructions.

Your doctor may also give you additional guidelines that cover:

  • Taking medications
  • Pregnant or breast feeding mothers
  • Flu or flu shot, shingles or TB
  • Bleeding conditions


During the procedure, a catheter is placed in the urinary bladder through the urethra. A local numbing medication, often a gel, may be used for the catheter insertion.1,2 It is generally not considered a painful procedure, though some may find it uncomfortable. Any urine remaining in the bladder will be drained and then a BCG solution will be inserted into the bladder next to the tumor and should remain for two hours. The catheter is normally removed after the BCG is placed into the bladder, and patients can get up and walk around during the waiting time. If the catheter is not removed for some reason, it is clamped to keep the BCG in the bladder. Patients are asked not to urinate for the two hours waiting time. Most people can travel independently to the doctor for the procedure, but it may be helpful to have another person accompany you to help pass the time.


After the BCG has been in the bladder for two hours, patients who have had the catheter removed are asked to urinate.1,2 Those who have had the catheter remain inserted during the waiting time will have the BCG drained before the catheter is removed. After the BCG is drained from the bladder, patients can resume drinking fluids normally.

Because BCG is a live vaccine, there are some important safety measures to keep in mind that your doctor can explain. BCG can remain in urine for 6 hours after your treatment, so each time you urinate, you should bleach the toilet in your home to neutralize the vaccine. If you are using a shared bathroom, you should make sure that no one uses the toilet directly after you until the bleach can take effect. It’s important to be mindful of small children and make sure you communicate with the members of your household about your treatment. Hand-washing and hygiene is important during your treatment and your doctor will provide specific safety instructions for after your treatment. Additionally, your doctor may advise you to refrain from oral sex or sexual intercourse for a few days after each BCG treatment. If you have any questions, make sure to ask your doctor.

BCG maintenance therapy

After the initial course of BCG treatment, it may be used again as maintenance therapy.1,2 Maintenance therapy is used to prevent bladder cancer from recurring and has been shown to reduce the frequency of recurrence and progression of bladder cancer. Treatment protocol intervals may vary, so patients could receive additional BCG treatments every 1, 3, or 6 months over a period of 1 to 3 years.

What are the side effects?

Some patients have difficulty completing long-term BCG therapy because of irritation in the bladder.2 To help with this irritation, the treatment frequency may be adjusted to give you a longer break between treatments. You may not notice any reaction after the first few BCG treatments. After the third treatment, patients usually start to experience bladder irritation pain or burning during urination, joint pain, fatigue, and flu-like symptoms that can last a few days. Most symptoms and side effects can be treated with over-the-counter pain medicines.

While BCG is a fairly common treatment for bladder cancer, every person has different experiences. It's important to talk to your doctor about any questions or concerns you may have at any point during your treatment. Being mentally prepared for what to expect can help to reduce stress or uncertainty about treatment or help you think of additional questions for your healthcare team.

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