Do prostate biopsies usually cause side effects?

Yes. The most common side effects are short term such as bleeding in the urine, bleeding in the stool, and blood in the sperm. Occasionally, a serious rectal infection can occur. Long term side are very rare.
Prostate biopsy. Transrectal or transperineal needle biopsies of the prostate are the only way to diagnose prostate cancer. The risk of infection can be minimized with proper prep of the rectum and pre- and post-procedure antibioitics.