Male libido is stimulated by the male hormone, testosterone, which is produced in the testicles. Patients who complain of loss of libido frequently have no problem with impotence, just with the sex drive. This is another problem area very commonly encountered in the practice of urology. Retrograde ejaculation can also be caused by certain medicines given to patients to relax the bladder neck to offset the effects of an enlarged prostate partially blocking the bladder neck. The emission phase of ejaculation will therefore propel the seminal fluid in a harmless way up into the bladder where it will be emptied the next time the patient urinates.

However, patients who have had prostate surgery, testicular cancer surgery, or are diabetic may have damage to some of the pelvic nerves that control and give muscle tone to the neck of the bladder. The fluid is then further propelled down the urethra and out the end of the penis by the rhythmic contraction of the pelvic floor muscles. During orgasm, the pelvic floor muscles spasm and the seminal fluid, stored in two small glands located behind the bladder, is pushed out into the urethra at a point about two inches downstream from the neck of the bladder. This term applies to the event that occurs when the bladder neck is open during ejaculation and the seminal fluid, rather than exiting the end of the penis, instead harmlessly flows into the bladder. A large number of other drugs, particu larly antidepressants, cause major problems with achieving orgasm in both males and females. Thus, some medicines that act as muscle relaxants can actually make having an orgasm quite difficult. Even though the orgasm process is primarily triggered by the excitation level of the patient, the end result is contraction of the pelvic floor muscles. At times they may not have an orgasm at all or may simply require an extensive length of time to reach an excitation and sensory level that triggers an orgasm. Patients who have performance anxiety regarding the act of sexual intercourse usually will also have problems having a timely orgasm. Diabetics often have a loss of sensation from genital stimulation due to diabetes-induced damage to the nerve fibers, resulting in decreased penile sensation during sex.