Combined intracavernous injection and stimulation test or CIS test is the most commonly performed office diagnostic procedure for erectile dysfunction

Erectile dysfunction

Erectile dysfunction is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance....

. It consists of an intracavernosal injection

Intracavernosal injection

An intracavernous injection is an injection into the base of the penis. This injection site is often used to administer medications to check for or treat erectile dysfunction in adult men .-References:...

, visual or manual sexual stimulation

Sexual stimulation

Sexual stimulation is any stimulus that leads to, enhances and maintains sexual arousal, and may lead to ejaculation and/or orgasm...

, and a rating of the subsequent erection

Erection

Penile erection is a physiological phenomenon where the penis becomes enlarged and firm. Penile erection is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal...

. Neurogenic and hormonal influences are thus bypassed as the status of the blood vessels of the penis

Penis

The penis is a biological feature of male animals including both vertebrates and invertebrates...

 is assessed directly and objectively. A rigid erection of more than 10 minutes indicates normal function of veins. The same conclusion cannot be made for the function of arteries as some men with mild arterial problems can also have the same response.