Overview of a Digital Rectal Exam

Understanding the Procedure and Its Limitations

gloved hand for medical procedure
Commercial Eye/The Image Bank/Getty Images

A digital rectal exam (DRE) is a simple procedure that men often dread, but one that can provide early detection of prostate cancer. It can also aid in the diagnosis of benign prostatic hyperplasia (an enlarged prostate) as well as conditions affecting men and women, including hemorrhoids, fecal impaction, or fecal incontinence.

A DRE is not used for the routine screening of prostate cancer but is rather an elective procedure performed in tandem with the prostate-specific antigen (PSA) blood test. On its own, DRE only offers 41 percent accuracy in correctly identifying a malignancy. It is most often used to support a diagnosis if a PSA result is borderline or a man is experiencing a weak urine flow and other symptoms with a normal PSA.

Despite the test's limitations, a DRE can provide insights that help characterize the nature of prostate or rectal disorder, including pain, bleeding and anal sphincter strength. It is not considered useful in diagnosing rectal cancer.

How It's Performed

The DRE is a relatively simple in-office procedure that does not require bowel preparation. After undressing below the waist and putting on a hospital gown, you will be lead to an examining room. Depending on the doctor, you will be placed in one of three positions:

  • Lying on your side on the exam table with one or both knees pulled toward your chest
  • Squat position with your forearms on the exam table
  • Lying on your back with your feet in a pair of stirrups, much like those for a gynecological exam

Once positioned, the doctor will put on a pair of latex gloves and examine the anus and perineum (the area between your genitals and anus) for any abnormalities. The doctor will then slip a lubricated finger into your rectum through the anus and examine the prostate gland or adjacent structures for anywhere from several seconds to a minute or so.

While the procedure may be uncomfortable, it rarely causes pain. Some people may experience bleeding, which is usually related to a thrombosed hemorrhoid or pre-existing anal fissure. If you experience any abnormal pain or sensation, let the doctor know. There are rarely any side effects associated with the DRE, including infection.

If you experience gas during the procedure or the doctor encounters fecal matter, know that this is not uncommon. While some people will use an anal douche to help clear the bowel beforehand, avoid excessive cleaning as this can make the tissues raw and inflamed.

Findings and Follow-Up

When used for a prostate exam, the DRE is designed to evaluate the size, consistency, and texture of the prostate gland.

If there are abnormal bumps or growths, your doctor will order one or several tests to confirm whether the growth is malignant or benign. Among them:

  • Core needle biopsy involves the insertion of a hollow-core needle into the growth to remove a small cylinder of prostate tissue. Most doctors will obtain 12 samples for a standard analysis.
  • Prostate magnetic resonance imaging (MRI) is an imaging test that uses magnetic fields and radio waves to visualize the area of growth. While less invasive than a biopsy, the procedure is known to miss up to 10 percent of small, high-grade tumors.

If your prostate is enlarged, but there are no abnormal growths and your PSA is normal, your doctor may order additional tests to establish the severity of the benign prostatic hyperplasia (BPH). Among them:

  • Uroflowmetry, which measures the volume of urine excreted during urination
  • Urodynamic tests, which look at how well the bladder, urethra, and urethral sphincters are storing and releasing urine
  • Post-void residual (PVR) studies, which measure how much urine is left in the bladder after urination

If you have fecal incontinence, often related to a neurologic disorder, a DRE can help evaluate the strength or laxity of the anal sphincter. Any abnormalities may be followed by additional tests to quantify the severity of the impairment:

  • Anorectal manometry measures the strength of the anal sphincter with a narrow, inflatable anal probe.
  • Proctography is an imaging test in which X-ray video footage is taken during a bowel movement.

If used to diagnose internal hemorrhoids, a DRE may be followed by anoscopy, a procedure in which a lighted fiberoptic scope can record images inside the rectum.

Prostate Cancer Screening Recommendations

In 2012, the U.S. Preventive Services Task Force (USPSTF) revised its recommendations regarding the use of the PSA and DRE in prostate cancer screening. The group advised against the routine screening of anyone other than men between 55 and 69 and those at increased risk of cancer, stating that the potential harms of treatment may likely outweigh the benefits.

This includes the overly aggressive treatment of low-grade cancer in younger men, which could lead to lifelong incontinence and erectile dysfunction. In men over 70, prostate cancer treatment rarely corresponds to a longer life.

While the USPSTF allows for the use of a PSA in screening, it advises against the DRE due to the lack of evidence supporting its ability to prevent disease or extend life.

For its part, the American Cancer Society takes a broader view of the DRE, stating that it has its place in screening if used alongside the PSA. The group also expanded their screening recommendations, advocating for elective screening at the following ages:

  • Age 50 for men who at average risk of prostate cancer who are expected to live for at least 10 more years
  • Age 45 for men at high risk, including African Americans and men with a first-degree relative (father, brother, or son) who had prostate cancer before age 65
  • Age 40 for men who had one more than one first-degree relative with prostate cancer before age 65

A Word From Verywell

While the digital rectal exam can provide considerable insight into the health of your prostate, it has its limitations. When combined with a PSA and other diagnostic tools (such as the fecal occult blood test), it can help point the doctor in the right direction without the need for more invasive (and costly) procedures.

A DRE should only be performed after discussing the benefits, limitations, and aims of the procedure. You can choose not to have a DRE and explore alternative forms of diagnosis. These include an abdominal ultrasound, which can visualize the prostate externally. If an internal examination is needed, most urology offices today are equipped with a transrectal ultrasound, a specialized ultrasonographic probe about the width of a finger.

Was this page helpful?
Article Sources