The usual cause of a bent penis during an erection is Peyronie's disease. Peyronie's disease is caused by a lump or scar tissue around the erection tissues of the penis. During an erection, the penis normally stretches. In Peyronie's disease, the scar tissue cannot stretch and so the penis bends towards the scar. Typically, the penis bends up, sometimes sideways but very rarely down. This bend can make it difficult to have sex. The process of scarring and bending takes place over about 6 months and you may feel a lot of pain whilst this is happening. The pain usually goes away over 6-12 months.
Most men who get Peyronie's disease are in their fifties. The cause is unknown though some believe that it is linked to repeated minor trauma during sex, which leads to abnormal healing and a scar forming. It is more common in people if they have a relative with the condition, or if they have an autoimmune disease (where the immune system attacks your own body) such as scleroderma (hardening of the skin) and Sjogren's syndrome.
Peyronie's disease can also occur after surgery for prostate cancer. It seems that the lack of erections (perhaps through low oxygen levels in the penis) leads to a scar forming.
Peyronie's disease is diagnosed by looking for a flat lump in the penis, a history of a bend in the penis with erections. The scar tissue usually can be felt though if there is any doubt, an ultrasound is taken to look at the scar tissue to confirm the diagnosis.
If you are able to have sex and the penis is not too sore, then doing nothing is often the best option. Aimed at making the scar softer, treatment options for Peyronie's disease include medication (tablets and or creams), using a stretching device, injections into the lump or surgery.
A new injection called Xiaflex (collagenase clostridium histolyticum) is now available for treating Peyronie's disease. Xiaflex is an enzyme, which breaks down the scar tissue when injected into the scar across the penis at the site of maximal bend. Two injections can be given about three days apart, hopefully creating a weak line in the scar so that the penis can be straightened. This procedure may need to be repeated up to three times. Xiaflex is licensed in Australia, but not yet in NZ. However, it can be imported from Australia on a named patient basis.In general, surgery is used only if the bend is so bad that you cannot have sex. The reason for avoiding surgery is that it will cause the penis to shorten and can cause a dimple or 'waistcoat effect' on the side of the penis. There are two different types of surgery and which is best for you depends on the where the scar tissue is and the extend of the bend. Pain is often a sign that the scarring process is still ongoing so surgery should not be considered until after the pain has settled.