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28227 Three Notch Road
Mechanicsville, MD 20659

Transrectal Ultrasound (TRUS)

A surgical procedure that uses sound waves to produce a video image of the prostate gland. A small, lubricated probe is placed into the rectum and releases sound waves, which create echoes as they enter the prostate. Prostate tumors sometimes create echoes that are different from normal prostate tissue. The echoes that bounce back are sent to a computer that translates the pattern of echoes into a picture of the prostate. While the probe may be temporarily uncomfortable, TRUS is essentially a painless procedure.

Why Is This Necessary?

TRUS is used to search for abnormalities in the rectum and nearby structures, including the prostate. Although TRUS alone cannot detect every tumor, it has been shown to detect some tumors that cannot be felt by a digital rectal examination. In addition, TRUS is used to estimate the size of the prostate gland, helping doctors get a better idea of PSA density, which helps distinguish benign prostatic hyperplasia (BPH) from prostate cancer. Finally, it plays a vital role in a prostate needle biopsy, guiding the needle to just the right part of the prostate gland.

TRUS can also be used to diagnose medial prostatic cysts, and diagnosing and draining prostatic abscesses or obstructed seminal vesicles.

The Procedure

You will need to have an enema prior to the procedure to remove any feces or gas that may obstruct the probe. During the procedure you will lie on your left side which allows for easier insertion of the probe and is generally more comfortable for the patient. The procedure will only take 5 to 15 minutes and is essentially painless, but there will be some discomfort associated with the probe being placed in the rectum.

If a biopsy is performed the use of anesthesia may be necessary. Your physician will inform you ahead of time what you should expect.

After the Procedure: If a biopsy was performed you should expect to see blood in your urine and semen for two weeks to two months. If you had anesthesia, be sure to have someone drive you home. You can return to normal activities as soon as you feel able.


As with any surgical procedure, there is a risk of swelling, bruising, and infection. Generally, for a person in good health without any serious underlying conditions, the risk is minimal.

If having a biopsy, you will also need to let your physician know if you take aspirin or a prescription blood thinner, and if you have any known allergies (especially to anesthetics such as Novocain).