Transrectal Ultrasound and Biopsy

Closeup cross section of prostate and rectum. Transducer is inserted into rectum and needle is inserted into prostate.

A transrectal ultrasound (TRUS) is an imaging test. It uses sound waves and a computer to create pictures of a man’s prostate gland. It doesn't use X-rays.

Your prostate gland is in front of your rectum. For this test, a special probe (called a transducer) is put into your rectum to see the prostate. During this test, tissue samples (called a biopsy) may be taken. TRUS is done by a specially trained technologist called a sonographer. It takes 15 to 30 minutes. It might take longer if a biopsy is done.

Getting ready for your test

  • You may be asked to clear your bowel before the test. This may be done by putting liquid into your rectum (an enema). Or you may be asked to drink a special liquid to clean out your colon and rectum.

  • You may be asked not to eat or drink anything after midnight the night before the test.

  • Tell your healthcare provider about any medicines, vitamins, herbs, or supplements you take. This includes any over-the-counter medicines such as aspirin or ibuprofen. You might need to stop taking some medicines, such as blood thinners, for a week or so before the test.

  • Answer any questions your healthcare provider has about your health history. This will help tailor the test to your health needs.

During your test

  • You will be asked to change into a hospital gown. You'll then lie on your side on an exam table, with your knees bent toward your chest.

  • The test is done with a hand-held probe. This is a short, slender rod about the size of your finger. It has a sterile, disposable cover on it. It's greased (lubricated) with some gel. It's gently put inside your rectum.

  • You'll feel pressure from the probe. If it hurts, let your healthcare provider know.

  • Sound waves are sent into the probe and through the wall of your rectum. They bounce off your prostate, and the computer uses them to form an image of the gland and nearby tissues. (It works much like sonar on a ship.)

  • If a biopsy is needed, you might be given medicine before the ultrasound to make you sleepy. This is done using a small probe with a very tiny needle on the end. This needle very quickly goes into your prostate many times and takes out tiny pieces (samples) of tissue. These samples are then sent to a lab to be tested. Any pain from the biopsy is usually mild. 

After your test

Before leaving, you may need to wait for a short time while the images are reviewed. In most cases, you can go back to your normal routine after the test. If you had a biopsy and took medicine to make you sleepy, you may need to wait until it has worn off before you can go home. You might see some blood in your urine, sperm, or stool for a day or so. This is normal. You may be asked to take antibiotics before and after TRUS if a biopsy is done. This is to help prevent infection.

Your healthcare provider will let you know when your test results are ready.

In some cases, a diagnosis can’t be made from the tissue sample that was taken. If this happens, your healthcare provider will talk with you about if you need another biopsy. Or you may need a different procedure.

When to call your healthcare provider

Call your healthcare provider if you have:

  • Very bloody urine or stool

  • A fever lasting 24 to 48 hours

  • Pain that's not getting better or that gets worse

  • Any other symptoms that your provider asks you to report, based on your health

Be sure you know what other problems you should watch for. Also know how to get help any time, including after office hours, on weekends, and on holidays.

Online Medical Reviewer: Kimberly Stump-Sutliff RN MSN AOCNS
Online Medical Reviewer: Lu Cunningham RN BSN
Online Medical Reviewer: Richard LoCicero MD
Date Last Reviewed: 7/1/2019
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