What Are Side Effects of BCG Live?

The most common side effects of BCG live are diarrhea, loss of appetite, nausea, tiredness and frequent or urgent urination, according to Drugs.com. Severe side effects, including blood in the urine, burning or pain during urination, flu-like symptoms, shortness of breath and muscle aches, warrant immediate medical attention.

BCG live is a strain of bacteria that is used to treat or prevent bladder cancer, states Drugs.com. It is usually instilled into the bladder via a urinary catheter in a doctor's office, clinic or hospital. Patients are instructed to lie on their stomachs for 15 minutes after BCG live is administered.