A prostate or rectal ultrasound is an imaging test that uses sound waves to look at your prostate or rectum.
The healthcare provider uses a small probe called a transducer to make images of your prostate or rectum. The transducer is about the size of a finger. It's gently placed into your rectum, where it sends out sound waves that bounce off your organs and other structures. The sound waves are too high-pitched for you to hear. The transducer then picks up the bounced sound waves. These are made into pictures of your organs.
Your provider can add another device called a Doppler probe to the transducer. This probe lets your provider hear the sound waves the transducer sends out. They can hear how fast blood is flowing through a blood vessel and in which direction it is flowing. No sound or a faint sound may mean that you have a blockage in the flow.
A prostate/rectal ultrasound may be used to check the size, location, and shape of the prostate gland and nearby structures. It may be used to look at the prostate gland for signs of cancer or other conditions. It’s often the next step after a finding of raised (elevated) prostate-specific antigen (PSA) during a blood test. Prostate/rectal ultrasound may be used to stage and watch treatment of rectal cancer. It's also used to look at the rectum for other problems.
Your healthcare provider may also use a prostate/rectal ultrasound to help place a needle to take a tissue sample (biopsy), which will be examined in a lab. Or they may do it to help place radiation seeds used to treat prostate cancer.
Your provider may also use the test to see how well blood is flowing to the prostate or find masses.
Your provider may have other reasons to recommend a prostate/rectal ultrasound.
An ultrasound has no risk from radiation. Most people have mild discomfort from the transducer being placed in the rectum.
Tell your healthcare provider if you're allergic to latex. The probe is placed in a latex covering before it's put into the rectum.
You may have risks depending on your specific health condition. Be certain your provider knows about all of your health conditions before the procedure.
Too much stool in the rectum may make the test less accurate.
Your healthcare provider will explain the procedure and you can ask questions. Make a list of questions and any concerns to talk about with your healthcare provider before the procedure. Consider bringing a family member or trusted friend to the medical appointment. They can help you remember your questions and concerns.
You'll be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something isn't clear.
You may be asked to stop taking blood-thinning medicines, such as aspirin, for a week or so before the test if it's being done as part of a biopsy. You may also be given a small enema if a biopsy is planned.
Follow any directions you're given for not eating or drinking before the test.
Follow any other instructions your provider gives you to get ready.
You may have a prostate/rectal ultrasound done as an outpatient or during a hospital stay. The way the test is done may vary depending on your condition and your healthcare provider's practices.
Generally, a prostate/rectal ultrasound follows this process:
You'll need to remove any clothing, jewelry, or other objects that may get in the way of the procedure.
If asked to remove clothing, you'll be given a gown to wear.
You'll lie on an exam table on your left side with your knees bent up to your chest.
The provider may do a digital rectal exam before the ultrasound.
The provider puts a clear gel on the transducer and puts the probe into the rectum. You may feel a fullness of the rectum at this time.
The provider will turn the transducer slightly several times to see different parts of the prostate gland and other structures.
If blood flow is being looked at, you may hear a whoosh, whoosh sound when the Doppler probe is used.
Once the test is done, the provider will wipe off the gel.
A prostate/rectal ultrasound may be uncomfortable. You'll need to remain still during the test. The gel will also feel cool and wet. The technologist will use all possible comfort measures and do the scan as quickly as possible to minimize any discomfort.
You don't need any special care after a prostate/rectal ultrasound. You may go back to your usual diet and activities unless your healthcare provider tells you otherwise.
Before you agree to the test or the procedure make sure you know:
The name of the test or procedure
The reason you are having the test or procedure
What results to expect and what they mean
The risks and benefits of the test or procedure
What the possible side effects or complications are
When and where you are to have the test or procedure
Who will do the test or procedure and what that person’s qualifications are
What would happen if you did not have the test or procedure
Any alternative tests or procedures to think about
When and how you will get the results
Who to call after the test or procedure if you have questions or problems
How much you will have to pay for the test or procedure