Prostate biopsies are an important tool for diagnosis prostate cancer. With local anaesthetic administration a prostate biopsy should not be painful but can be uncomfortable for some. It's not unusual to notice blood in the urine, stool and semen afterwards. Usually this is slight but in the minority this can be heavy or prolonged. Antibiotics are given to reduce the risk of an infection caused by normal bacterial flora within in the rectum being pushed into the urine or blood stream by the biopsy needle. Despite the antibiotics about 1 in 20 patients will develop a urine infection or septicemia requiring further antibiotics occasionally intravenously. Some men may suffer difficulty passing urine in the first day or two after the biopsy. Rarely this may require the temporary insertion of a catheter to relieve it.