A transrectal ultrasound is often used to help diagnose prostate cancer if the prostate-specific antigen (PSA) level is high, the doctor feels an abnormal area during a digital rectal exam (DRE), prostate cancer is suspected after a magnetic resonance imaging (MRI)-ultrasound fusion targeted biopsy, or a man has certain symptoms, such as trouble urinating.

A transrectal ultrasound is done to:

• look for abnormal areas in the prostate
• guide a needle during a biopsy to collect samples from the prostate
• look at the size and shape of the prostate

• A transrectal ultrasound biopsy is usually have under local anesthetic, so you can generally eat and drink normally beforehand. In case if doing under sedations, you need to fast before the procedure as doctor’s recommendation.
• You may need to undergo some tests before the procedure, such as blood tests, chest x-ray, and electrocardiogram (EKG).
• You may take your normal medication unless your doctor says otherwise. Blood-thinning medications like warfarin and aspirin will need to be stopped before the procedure to prevent excessive bleeding. Please let your doctor know about all medication you are taking.
• You may receive oral or intravenous antibiotics to prevent infection.
• You will be given an enema to empty your bowels for the biopsy.

First, you lie down on your left side. Your specialist injects local anesthetic into your rectum, to numb the area. It makes the procedure as painless as possible. The doctor puts an ultrasound probe into your rectum to examine your prostate. To get the samples of prostate tissue, they push the fine needle along the ultrasound probe and into the prostate gland. This is a little uncomfortable and might be painful, but does not take long. You feel a slight jolt each time the doctor fires the needle. The procedure takes about 15-30 minutes.
 

• You will be given antibiotic tablets and painkillers to take after the procedure.
• You may experience some perineal pain or discomfort after the procedure.
• You can expect to see some blood in your urine for 1-2 days following the biopsies. You may notice some blood in your semen for six weeks to three months. If the bleeding becomes excessive, prolonged or if you start to pass blood clots then you should seek medical attention.
• Occasionally swelling may occur in the prostate gland as an inflammatory response to the biopsies being taken. This can cause difficulty in passing urine and may very occasionally cause the ability to pass urine to stop completely. This is known as urinary retention and you would then need a catheter inserted to drain your bladder for a few days.
• You may also find that it may sting or irritate the urethra the first few times that you pass urine after the biopsy.
• If you develop flu-like symptoms within 24 hours of the biopsies being taken (fever, cold shivers, general aching) you should seek medical assistance immediately. You should drink plenty of fluids.
• You can usually return to work the day after you have been discharged from hospital, if you feel ready to do so. It may be difficult sitting down for prolonged periods of time for the first 2-3 days.
• The biopsy result will approximately some few days to be sent back from the pathology laboratory. Your consultant will make a follow-up arrangement for you before you are discharged from the hospital.

• Infection (Two in 100 men will experience this.) There is a risk of infection at the biopsy site because the rectum wall is not sterile. The doctor will prescribe you antibiotics before and after your biopsy to reduce this risk. If you have a high fever, please contact your doctor.
• Bleeding in the urethra or bladder wall (often know as urinary clot retention) for five in 100 men experience this. This can cause a hematoma (blood blister), which can make it difficult for you to pass urine, or make you pass urine frequently. If you are unable to pass urine at all you should contact your doctor.
• Blood in your urine. Most patients will have some blood in their urine for two to three weeks after this procedure. If this continues for longer, please contact your doctor.
• Bleeding from rectum. This common and eight out of 10 men will experience this during the first two days after the biopsy, but should not last more than two weeks. If you have heavy bleeding or start passing large clots of blood at any time following the procedure, please contact your doctor.
• Blood in your semen. Most patients will have some blood in their semen for up to six weeks after this procedure. If this continues for longer, please contact your doctor.

• If you are taking any blood-thinning medication/anticoagulant, please let your doctor know as some may need to be stopped before you travel for the procedure.
• Travelers to Thailand should plan to stay in the country for at least one week or for the entire duration of treatment.
• If you plan to return home after the procedure, please speak to your doctor before making travel arrangements. There are no restrictions for air travel.
• During your follow-up appointment your medical team will assess your health and your incision and you will receive documents detailing your medical and treatment history and your "Fit to Fly" certificate (if needed).

The success of the procedure depends on a number of factors. Please discuss the likelihood of success with your doctor before the procedure.
 
What if the procedure is not performed?
A biopsy helps diagnose and stage prostate cancer as well as any changes in the cancer cells and it can diagnose benign prostate hyperplasia, which is the enlargement of the prostate. The diagnosis will then help your doctor plan your future care. Please discuss specific risks of not having the procedure done with your doctor.
 

There is presently no other standard method for diagnosing prostate cancer.