Prostatic calculi (stones) are very common. They aren't always apparent during a rectal exam or on X-rays.

Prostate stones are usually tiny—about the size of poppy seeds—and do not cause symptoms.

In some men, infected prostate stones may cause recurrent urinary tract infections (UTIs) and make it difficult to cure bacterial prostatitis. The stones may have to be removed with surgery before UTIs or chronic prostatitis can be resolved.