If your doctor is concerned that you may have prostate cancer, they will arrange for you to have a trans-rectal ultrasound guided prostate biopsy (TRUS). This is a common procedure, usually performed as a day case in a hospital under local anaesthetic.
An ultrasound probe is placed into the back passage using some lubricating jelly. This is moved around whilst the doctor or nurse scans through your prostate to measure its size and to see if there are any abnormal areas. Local anaesthetic is then injected around the gland - this does not hurt, but might give the sensation that you want to pass water. Then the biopsies (small samples of tissue) are taken with a spring-loaded instrument that makes a loud noise. This is not painful but the noise can sometimes be a little frightening. Usually 10 biopsies are taken, unless you have had previous biopsies in which case more may be taken.
After the biopsy, it is very normal to see blood in the water and from the back passage. This usually passes after a day or so. It is also very normal to see blood in the ejaculate (semen), which can last for weeks and depends how often you are sexually active. Infection is a risk with these biopsies so you will be given antibiotics to try to prevent this.
What happens if I have no back passage? If your back passage has been removed from previous surgery, biopsies are usually taken transperineally. This means using an ultrasound probe from the front and the needle to take the biopsies is passed through the skin behind the scrotum in front of the area where your back passage would have been (perineum). The after effects are similar to a biopsy taken via the back passage.