FTM bottom surgery refers to two main procedures: metoidioplasty and phalloplasty. Each takes a fundamentally different approach to constructing a penis, and the choice between them shapes everything from the number of surgeries involved to the final size, sensation, and function. Most people pursue one or the other, though some start with metoidioplasty and later opt for phalloplasty.
Metoidioplasty: Using What Testosterone Has Built
Metoidioplasty works with tissue you already have. After months or years on testosterone, the clitoris grows significantly. Metoidioplasty releases this enlarged tissue from its surrounding structures, straightens it, and lengthens it to create a small phallus. The surgeon divides the ligaments holding the clitoris in place and reshapes the surrounding skin from the labia minora to create a natural-looking penoscrotal angle.
The final size depends on how much growth testosterone produced before surgery. In a study of 813 cases published in Frontiers in Endocrinology, the average length of the resulting phallus was 5.6 cm, with a range of about 4.8 to 10.2 cm. Because the tissue retains its original nerve supply, erotic sensation is preserved, and erections happen naturally without implants. The trade-off is size: a metoidioplasty phallus is typically not large enough for penetrative sex, though standing urination is possible if urethral lengthening is included.
Metoidioplasty is a shorter, less complex procedure than phalloplasty, often completed in one or two stages with a faster recovery.
Phalloplasty: Building a Full-Size Phallus
Phalloplasty constructs a full-size penis using a large flap of skin, fat, and blood vessels taken from a donor site on your own body. The two most common donor sites are the forearm (radial forearm flap) and the outer thigh (anterolateral thigh flap). The forearm flap is considered the standard because the skin is thinner and tends to produce better tactile sensation. The thigh flap avoids the visible forearm scar, which is a significant cosmetic concern for many people, but it may require additional revision procedures.
In the operating room, the surgeon harvests the tissue flap, shapes it into a cylindrical phallus, and microsurgically connects its blood vessels and nerves to those in the groin. A nerve from the donor flap is joined to a nerve in the genital area, which over the following months allows sensation to gradually develop in the new phallus. This nerve regrowth is slow, often taking a year or more, and the degree of sensation varies from person to person.
How Urethral Lengthening Works
For many transmasculine people, being able to urinate standing up is a major goal. Achieving this requires urethral lengthening, one of the most technically demanding parts of bottom surgery.
The new urethra is built in two sections. The “fixed” portion, closer to the body, is constructed by mobilizing the inner lining of the labia minora and rolling it into a tube around a catheter. Muscle and tissue are layered over this section for support. The “pendulous” portion, which runs through the shaft of the phallus, can be created from forearm skin (in a forearm flap phalloplasty), from a separate skin flap near the hip, or from labial tissue. When labial tissue is used, the resulting tube is roughly 8 to 10 cm long.
Urethral lengthening is optional for both metoidioplasty and phalloplasty. Skipping it significantly reduces complication risk, but means you would continue sitting to urinate.
Scrotoplasty and Testicular Implants
Scrotoplasty creates a scrotum from the labia majora. The most common technique involves V-Y advancement flaps, where the labial tissue is repositioned and fused at the midline to form a single pouch that resembles a natal scrotum. Testicular implants (silicone prostheses) are placed inside to give it a natural shape and weight.
Surgeons have shifted toward placing these implants in a later, separate stage rather than at the time of initial construction. Smaller, lighter prostheses are now preferred, and waiting allows the tissue to heal fully before adding the implants.
Erectile and Testicular Implants
A phalloplasty does not produce natural erections because the constructed tissue lacks the spongy erectile bodies found in a natal penis. To enable penetrative sex, an erectile device is implanted in a later surgical stage, typically the final one.
Two types exist. Inflatable implants use a pump (placed in the scrotum) that fills cylinders in the shaft with fluid, creating a rigid erection on demand and deflating afterward. Semi-rigid implants are flexible rods that remain firm and are simply bent upward for sex and downward for concealment under clothing. Inflatable devices feel more natural but have more mechanical parts that can eventually need replacement. Both types require that the phallus has fully healed and developed adequate protective sensation to prevent injury to the implant site.
Surgical Stages and Timeline
Phalloplasty is not a single operation. It is typically split into three stages:
- Stage 1: Formation of the phallus and, if desired, construction of the new urethra within the shaft.
- Stage 2: Glans sculpting (shaping the head of the penis for a natural appearance), scrotoplasty, and connecting the new urethra to the bladder.
- Stage 3: Placement of erectile and testicular implants.
Each stage requires at least three months of healing before the next, and the surgeon will not schedule the following procedure until recovery from the previous one is complete. Even without complications, the entire process typically takes 12 to 18 months. In practice, accounting for scheduling, work, and life logistics, many people find the full process takes two to three years.
Preparation Before Surgery
If you are pursuing urethral lengthening, one critical preparation step is permanent hair removal on the donor site. The strip of skin that will become the inner lining of the urethra must be completely free of hair follicles. Hair growing inside a urethra can cause blockages, infections, and stones. Laser hair removal or electrolysis on the relevant area must be completed at least three months before surgery to confirm the results are lasting.
Current standards of care require two mental health assessment letters for genital surgery, at least 12 months of hormone therapy (if medically appropriate), and at least 12 months of living in your affirmed gender role. Once staged procedures begin, you do not need to resubmit assessment letters for subsequent stages.
Complication Rates
Bottom surgery, particularly phalloplasty with urethral lengthening, carries significant complication rates that are important to understand going in. The most common problems involve the constructed urethra. A meta-analysis covering published outcomes found that about 24% of phalloplasty patients experienced a urethral fistula (an abnormal opening where urine leaks through the shaft) and that the combined rate of any urethral fistula or narrowing was around 49%. Non-urethral complications, including partial tissue loss, infection, blood vessel problems, and delayed wound healing, occurred in roughly 19% of patients.
These numbers sound high, and they are. Most urethral fistulas and narrowings are correctable with additional minor procedures, which is one reason the overall surgical journey often extends well beyond the planned stages. Surgical teams with high case volumes tend to report better outcomes, so choosing an experienced center matters. Patients who opt out of urethral lengthening see a dramatically lower complication profile, which is why some people make that trade-off deliberately.
Metoidioplasty vs. Phalloplasty
The choice between the two procedures comes down to priorities. Metoidioplasty preserves natural erotic sensation and erectile function, involves fewer surgeries, has a shorter recovery, and carries lower complication risk. The result is a smaller phallus that typically cannot be used for penetrative sex.
Phalloplasty creates a full-size phallus that can accommodate an erectile implant for penetrative sex and generally provides a more typical male appearance when clothed or undressed. It requires multiple surgeries over one to three years, leaves a visible scar at the donor site, and carries higher complication risk, especially when urethral lengthening is included. Sensation develops gradually and varies in degree.
Neither option is universally “better.” Some people prioritize sensation and simplicity. Others prioritize size and penetrative function. Some choose metoidioplasty first, live with the results, and later pursue phalloplasty if they want more. The decisions are deeply personal, and most surgical teams walk through these trade-offs in detail during consultation.