Prostate Cancer: Prostate Ultrasound and Biopsy

Prostate ultrasound and biopsy both evaluate the abnormal results of a digital rectal exam or an elevated prostate-specific antigen (PSA) blood test.

Prostate ultrasound involves a probe about the size of a finger that is inserted a short distance into the rectum. This probe produces harmless high-frequency sound waves, inaudible to the human ear, that bounce off the surface of the prostate. The sound waves are recorded and transformed into video or photographic images of the prostate gland.

The probe can provide images at different angles to help your doctor estimate the size of your prostate and detect any abnormal growths.

A prostate biopsy uses transrectal ultrasound (through the rectum’s lining) imaging to guide several small needles through the rectum wall into areas of the prostate where abnormalities are detected. The needles remove a tiny amount of tissue. Usually six or more biopsies are taken to test various areas of the prostate. The tissue samples are then analyzed in a laboratory. The results will help doctors diagnose disorders and diseases in the prostate. If cancer is identified, the doctor will be able to grade the cancer and determine its aggressiveness or likelihood of spreading.

Some doctors perform the biopsy through the perineum (skin between the scrotum and rectum). Researchers are investigating alternative biopsy procedures in efforts to maximize the accuracy of these results.

What Happens Before The Procedure?

Here's how to get ready for the ultrasound and biopsy.

Special conditions

Tell your doctor if you have a lung or heart condition or any other diseases, or if you are allergic to any medicines.

Tell your doctor if you have an artificial heart valve or if you have ever been told you need to take antibiotics before a dental or surgical procedure. If you have any of these conditions, you will be given antibiotics to take before the biopsy.



Tell your primary doctor if you are taking warfarin (Coumadin), clopidogrel (Plavix), rivaroxaban (Xarelto) or other blood thinners. He will tell you if these medicines need to be discontinued about one week before the procedure. Your primary doctor may prescribe an alternate method for thinning your blood before the procedure.

The week before the procedure, do NOT take aspirin, products containing aspirin, or anti-inflammatory drugs (such as ibuprofen (AdvilMotrin), naproxen (Naprosyn) or indomethacin (Indocin).

You will receive antibiotics to take the night before the procedure or the morning of the procedure to prevent infection.

* Do not discontinue any medication without first consulting your primary or referring physician.

Eating and drinking

Eat a light breakfast or lunch before the procedure and drink only clear liquids (which include juices, broths, and gelatin) the morning of the procedure.


You will receive one enema before the procedure to empty your colon and minimize the risk of infection during the procedure. You may be asked to use the enema at home. Try to hold the enema solution for at least five minutes before releasing it.

What Happens on the Day of the Procedure?

A doctor or nurse will explain the procedure in detail, including possible complications and side effects. You will also be able to ask questions.

What Happens During the Procedure?

The procedure is performed by a doctor experienced in prostate ultrasound and biopsy. It will last 10 to 20 minutes.

You will lie on your left side, with your knees drawn up.

The ultrasound probe will be inserted into the rectum and the biopsies will be taken. You may feel discomfort as the biopsies are being taken. A local numbing medication may be used to control some of this discomfort.

What Happens After the Procedure?

The biopsy will be sent to a lab for analysis. Your doctor will discuss the results with you when they are available (usually within one week after the biopsy). Meanwhile:

  • You may resume your normal meals and activities.
  • For at least three days after the procedure, do NOT take aspirin, products containing aspirin, or anti-inflammatory drugs (such as Advil, Motrin or Naprosyn), or indomethacin (Indocin).
  • Drink six to eight glasses of water every day for three days after the procedure to help flush your urinary system.
  • You may notice a small amount of blood in your urine, semen, or stool up to seven days after the procedure. This is normal.
  • If you have any rectal soreness, soak in a warm bath for 20 minutes to relieve discomfort.
  • Take all of the antibiotics until all pills gone. If you miss a dose, take it when you remember and then maintain your regular schedule.


When Should I Call My Doctor?

Call the nearest emergency department if:

  • You have a fever above 100.4 degrees F (38 C)
  • You have difficulty urinating
  • Your urine becomes bloody and does not clear after drinking extra fluids
  • A blood clot forms in your urine
WebMD Medical Reference Reviewed by Jennifer Robinson, MD on October 19, 2017



American Cancer Society. 

American Urological Association.

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