A transrectal ultrasound (TRUS) uses high-frequency sound waves to create images of the prostate, rectum, and other nearby pelvic organs, primarily in men. A long, narrow transducer is inserted into the rectum to generate a sonogram, or picture, of the area. TRUS is used to diagnose prostate conditions, such as tumors or abnormal growths, guide a prostate biopsy, and evaluate for causes of infertility or difficulty urinating.