Preparing for a prostate biopsy involves managing medications, following bowel prep instructions, and planning logistics like fasting and transportation depending on your type of anesthesia. Most of the preparation happens in the week before the procedure, with a few steps on the morning of. Here’s what to expect and how to get ready.
Know Which Type of Biopsy You’re Having
There are two main approaches, and your preparation differs slightly depending on which one your urologist recommends. A transrectal biopsy uses an ultrasound probe inserted through the rectum. A transperineal biopsy uses a needle through the skin between the scrotum and rectum. The transperineal approach has been gaining ground because it carries virtually zero risk of infection. A large 10-center clinical trial published in JAMA Oncology found zero infections among 372 patients who had transperineal biopsies, compared to a 1.6% infection rate in the transrectal group. Because of this difference, transperineal biopsies often skip antibiotic prophylaxis entirely, while transrectal biopsies require antibiotics beforehand.
Ask your urologist which approach they’ll use. This single detail shapes several other preparation steps.
Managing Blood Thinners and Medications
If you take blood thinners or antiplatelet medications like warfarin, dabigatran, or rivaroxaban, your doctor will likely ask you to stop them about one week before the biopsy. This is standard practice recommended by both the Korean Society of Urogenital Radiology and the Canadian Urologic Association to reduce bleeding risk.
Aspirin is a special case. Research pooling data from over 3,300 patients found that continuing aspirin before a transrectal biopsy slightly increased rectal bleeding but did not significantly raise the risk of blood in the urine or semen. Some urologists now consider it safe to continue low-dose aspirin, though others still prefer you stop. Don’t make this call on your own. Your urologist needs to weigh the bleeding risk of the biopsy against the cardiovascular risk of pausing your medication, so have that conversation early.
Bring a complete list of everything you take, including supplements like fish oil and vitamin E, which can also affect clotting.
Antibiotics Before the Procedure
If you’re having a transrectal biopsy, you’ll be prescribed antibiotics to take before the procedure. The American Urological Association recommends a single dose, timed to be active in your system when the biopsy begins. Some practices also do a rectal swab ahead of time to check for antibiotic-resistant bacteria so they can tailor the prescription to you specifically.
If you’re having a transperineal biopsy, you may not need antibiotics at all. Because the needle never passes through the rectum, the risk of introducing gut bacteria into the prostate is essentially eliminated.
Bowel Preparation
For a transrectal biopsy, you’ll typically be asked to do a cleansing enema at home the morning of your appointment. Mayo Clinic includes this as a standard instruction. Fleet enemas are the most commonly recommended type and are available over the counter. Follow the timing your clinic provides, which is usually one to two hours before you leave for your appointment.
Dietary restrictions before the procedure vary by practice. Some clinics ask you to eat lightly the evening before and avoid heavy, greasy foods. Others have no specific dietary instructions beyond the enema. Check with your scheduling nurse for your clinic’s specific protocol.
Fasting, Sedation, and Getting Home
Your fasting requirements depend entirely on the type of anesthesia. If you’re getting local anesthesia (the most common approach for in-office biopsies), you can eat and drink normally before the procedure. Most transrectal biopsies and many transperineal biopsies use local anesthesia with a numbing injection near the prostate.
If your biopsy is scheduled under general anesthesia or IV sedation, you’ll need to stop eating at least six hours beforehand and stop drinking liquids at least four hours before. You’ll also need a designated driver to take you home afterward, since you won’t be cleared to drive the same day. Even if you feel fine after sedation wears off, your reaction time remains impaired for hours.
If you’re having local anesthesia only, most clinics allow you to drive yourself, but it’s still worth having someone available in case you feel lightheaded or uncomfortable afterward.
What to Expect During Recovery
The biopsy itself takes about 10 to 20 minutes, but the aftereffects last longer. Blood in the urine is the most common side effect, appearing in roughly 47% to 58% of patients. It’s usually most noticeable on the first day, when about 39% to 53% of patients see it, and drops significantly by day two. Rectal bleeding occurs in about 10% to 37% of patients, again most prominent on day one.
Blood in the semen is actually the single most common complication overall, and it can persist for weeks, sometimes even a couple of months. This looks alarming but is harmless. The discoloration gradually fades as the prostate heals.
Most men can return to normal activities within a day or two, though you’ll want to avoid heavy lifting and strenuous exercise for about 48 hours. Staying well hydrated helps flush blood through the urinary tract more quickly.
Warning Signs After the Biopsy
Some bleeding is expected, but certain symptoms need immediate attention. A high fever in the days following the biopsy is the most important red flag, as it can signal an infection that needs urgent treatment. Most biopsy-related infections develop within seven days. Heavy bleeding that doesn’t slow down, an inability to urinate, or increasing pain rather than decreasing pain also warrant a call to your urologist or a trip to the emergency department.
When You’ll Get Results
Pathology labs typically process biopsy tissue in two to three working days. Your urologist’s office may take a few additional days to review and schedule a follow-up, so most patients hear back within one to two weeks. The report will include a Gleason score if cancer cells are found, which grades how aggressive the tissue looks under a microscope. If no cancer is detected, the report will describe the tissue as benign.
The waiting period is often the hardest part. Some clinics offer patient portal access where results post automatically, while others prefer to discuss findings by phone or in person. Ask your care team ahead of time how and when you’ll receive your results so you’re not left checking your phone every hour.