Diphallia: Causes, Symptoms, and Treatment
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Diphallia?
A urologist, a doctor who treats the urinary tract and male genitals, usually leads care for diphallia. Children are often seen by a pediatric urologist or a pediatric surgeon. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is diphallia?
Diphallia, also called penile duplication, is an extremely rare birth defect. A person is born with a doubled penis. It occurs once in every 5.5 million live births. Only about 100 cases have been reported in medical writing.
The doubling can look very different from person to person. It ranges from a small extra penis or a double tip to two complete penises. Doctors sort it into two main groups, true diphallia and bifid phallus. Each group is divided into partial or complete duplication.
Symptoms
Signs depend on the type. They can include:
- Two separate penises, which may be the same size or different sizes.
- A smaller, underdeveloped second penis.
- A urine opening that is in a normal or unusual place.
- A scrotum that is normal or split in two, called a bifid scrotum.
- Testes that are normal, underdeveloped, or not in their usual place.
- Urine that leaks or dribbles.
Erections vary. Usually one or both penises can have an erection.
Diphallia is usually linked with other birth defects. These can include a double bladder or urethra, which is the tube that carries urine out, and problems with the anus and rectum. They can also include a belly wall hernia and differences in the spine bones. True diphallia is more often linked with severe birth defects than bifid phallus.
Causes and who gets it
Doctors do not know the exact cause. Many ideas have been offered, but none explains every case. It is believed to happen during early development of the penis, around the 3rd to 6th week of pregnancy. One theory is that an early disturbance from injury, drugs, or infections plays a part. Chromosome tests have usually been normal.
The condition is present from birth.
How doctors diagnose it
Doctors study the outside of the genitals closely. This helps sort the type and plan surgery. Ultrasound can help confirm the diagnosis. MRI is a scan with no needles or cuts. It is used to study complex anatomy.
Every person needs a careful, complete check for other birth defects. In one case report, doctors used a chromosome test, X-rays, ultrasound, a CT scan, kidney imaging, and a bladder and urethra X-ray test called voiding cystourethrography.
Treatment
Treatment is surgery. The usual approach is to remove the extra penis. In some people, surgeons have rebuilt the penis by joining parts of the two. Each plan is made for the person. It depends on any other birth defects and on keeping urine control and erection.
The goals are good urine control, a good urine stream, erection, and a normal look. In reported cases, related birth defects were repaired too. These choices can be hard, with medical, ethical, and appearance questions to weigh. The outlook depends largely on whether the doubling is the only problem or comes with many other defects.
When to see a doctor
A baby or child with a doubled penis needs a careful, complete check by a doctor for related problems. Babies with diphallia and related conditions have a higher death rate from infections linked to complex kidney or bowel systems. Ask the care team which signs of infection need care right away. Call 911 or go to the emergency room if a child has trouble or abnormal breathing, bluish or grey skin, a seizure, or fever followed by a change in mental status or stiffness in the neck or back.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either kind of doctor can help a family understand the diagnosis, arrange first checks, and coordinate visits with a urologist and other specialists.
Common questions
How common is diphallia?
It is extremely rare. It occurs once in every 5.5 million live births. Only about 100 cases have been reported in medical writing.
Can a person with diphallia have erections?
Often, yes. Usually one or both penises are capable of erection, but erectile function varies widely from person to person.
Does diphallia come with other birth defects?
Yes. Diphallia is usually linked with other birth defects, such as a double bladder or urethra. Doctors check for these problems in every case.
Is diphallia life-threatening?
It depends on whether other birth defects are present. The outlook depends largely on whether the doubling is the only problem. Babies with related kidney or bowel problems have a higher death rate from infections.
Sources
- National Library of Medicine (PMC) - Diphallia with Associated Anomalies: A Case Report and Literature Review
- National Library of Medicine (PMC) - A rare case of isolated complete diphallia and review of the literature
- National Library of Medicine (PMC) - Diphallus: Report on Six Cases and Review of the Literature
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
