Many older men are seen for a physical examination that reveals an elevated PSA, which may lead to a prostate puncture biopsy. When is a prostate puncture biopsy necessary? Elevated serum PSA can also be caused by other reasons. A rectal finger test can cause an elevated PSA, but this elevation does not seem to affect the diagnosis of prostate cancer. Medical manipulation of the prostate such as prostate massage, cystoscopy, catheterization, and prostate puncture can all raise serum PSA. Ejaculation, acute prostatitis, and urinary retention can also cause an elevation of serum PSA. In general, if your serum PSA is still higher than the normal range after eliminating the above mentioned factors that may cause it, it is recommended that you see a urologist for a rectal examination and, if necessary, a prostate puncture biopsy. A transrectal ultrasound-guided prostate puncture biopsy is usually performed in the ultrasound room. You should stop taking anticoagulants such as aspirin and warfarin for at least 2 weeks prior to this test (if you have had previous heart valve replacement surgery, you should give your urologist instructions and determine when to stop or how to reduce the dosage), as bleeding is likely to occur if you do not stop. Because the rectum is the most terminal part of the gastrointestinal tract and contains a large number of gram-negative bacteria, you will need an enema to cleanse your rectum and intravenous antibiotics to prevent infection prior to this test. For this test, the doctor usually has you lie on your left side with your legs tucked in. An ultrasound probe about the thickness of your thumb is inserted into your rectum without any anesthesia, and a slight discomfort is experienced. There is a slight pain during the puncture, which is usually tolerated by people.