Benign prostatic enlargement (BPE) is an increase in the volume of the prostate gland which can be detected by digital rectal examination (DRE) or more accurately by transrectal ultrasound (TRUS). BPE may be due to benign prostatic hyperplasia (BPH) which is a histological diagnosis characterized by a combination of atrophy and proliferation in both glandular and stromal tissue. The onset of BPH is dependent on the presence of testes and increasing age. The first pathological signs appear under the age of 40 years followed by a rapid increase in prevalence with age: 80% of 80-year-olds have evidence of BPH. Bladder outlet obstruction (BOO) is defined by pressure-flow studies (PQS) and may be due to benign prostatic obstruction (BPO).