Frisch & Simonsen (2016) carried out a very large scale study in Denmark, which compared the incidence of meatal stenosis in Muslim males (mostly circumcised) with the incidence of meatal stenosis in ethnic Danish males (mostly non-circumcised). The risk of meatal stenosis in circumcised males was found to be as much 3.7 times higher than in the intact, non-circumcised males.

Urethral strictures most commonly result from injury, urethral instrumentation, infection, non-infectious inflammatory conditions of the urethra, and after prior hypospadias surgery. Less common causes include congenital urethral strictures and those resulting from malignancy.

Urethral strictures after blunt trauma can generally be divided into two sub-types;

- Pelvic fracture-associated urethral disruption occurs in as many as 15% of severe pelvic fractures. These injuries are typically managed with suprapubic tube placement and delayed urethroplasty 3 months later. Early endoscopic realignment may be used in select cases instead of a suprapubic tube, but these patients should be monitored closely as vast majority of them will require urethroplasty.

- Blunt trauma to the perineum compresses the bulbar urethra against the pubic symphysis, causing a "crush" injury. These patients are typically treated with suprapubic tube and delayed urethroplasty.

Other specific causes of urethral stricture include:

- Instrumentation (e.g., after transurethral resection of prostate, transurethral resection of bladder tumor, or endoscopic kidney surgery)

- Infection (typically with Gonorrhea)

- Lichen sclerosus

- Surgery to address hypospadias can result in a delayed urethral stricture, even decades after the original surgery.

The use of bioengineered urethral tissue is promising, but still in the early stages. The Wake Forest Institute of Regenerative Medicine has pioneered the first bioengineered human urethra, and in 2006 implanted urethral tissue grown on bioabsorbable scaffolding (approximating the size and shape of the affected areas) in five young (human) males who suffered from congenital defects, physical trauma, or an unspecified disorder necessitating urethral reconstruction. As of March, 2011, all five recipients report the transplants have functioned well.

The main infectious agents are Enterobacteriaceae (such as Escherichia coli and Klebsiella), Neisseria gonorrhoeae and Chlamydia trachomatis.

One study has shown that men with MAGI who have lower serum levels of total testosterone tend to have a more complicated form of MAGI, such as involving more than one site, than those with normal levels.

Numerous studies over a long period of time clearly indicate that male circumcision contributes to the development of urethral stricture. Among circumcised males, reported incidence of meatal stricture varies. Griffiths "et al". (1985) reported an incidence of 2.8 percent. Sörensen & Sörensen (1988) reported 0 percent. Cathcart "et al". (2006) reported an incidence of 0.55 percent. Yegane "et al". (2006) reported an incidence of 0.9 percent. Van Howe (2006) reported an incidence of 7.29 percent. In Van Howe's study, all cases of meatal stenosis were among circumcised boys. Simforoosh "et al". (2010) reported an incidence of 0.55 percent. According to Emedicine (2016), the incidence of meatal stenosis runs from 9 to 20 percent. Frisch & Simonsen (2016) placed the incidence at 5 to 20 percent of circumcised boys.

Potential complications include:

- obstruction of the epididymis

- impairment of spermatogenesis

- impairmentment of sperm function

- induction of sperm auto-antibodies

- dysfunctions of the male accessory glands

These complications can result in

sexual dysfunction and male subfertility.

There are two types of prostatic stent: temporary and permanent.

Although a permanent prostatic stent is not a medical treatment, it falls under the classification of a surgical procedure. Placement of a permanent prostatic stent is carried out as an outpatient treatment under local, topical or spinal anesthesia and usually takes about 15–30 minutes.

A temporary prostatic stent can be inserted in a similar manner to a Foley catheter, requiring only topical anesthesia.

Even with successful surgery, patients may have long-term problems with:

- incontinence, where serious usually treated with some form of continent urinary diversion such as the Mitrofanoff

- depression and psycho-social complications

- sexual dysfunction

When an infant is born with PSH, the most difficult management decision has often been the sex assignment, since genitalia with this degree of ambiguity do not resemble either sex very well with respect to looks or function. Many infants with PPHS have been assigned and raised as female despite presence of testes and XY chromosomes.

Nearly all parents of infants with PPSH are offered surgical reconstruction, to either further masculinize or feminize the external genitalia.

Treatment with testosterone postnatally does not close the urethra or change the malformation, but in some cases may enlarge the penis slightly.

A prostatic stent is a stent used to keep open the male urethra and allow the passing of urine in cases of prostatic obstruction and lower urinary tract symptoms (LUTS). Prostatic obstruction is a common condition with a variety of causes. Benign prostatic hyperplasia (BPH) is the most common cause, but obstruction may also occur acutely after treatment for BPH such as transurethral needle ablation of the prostate (TUNA), transurethral resection of the prostate (TURP), transurethral microwave thermotherapy (TUMT), prostate cancer or after radiation therapy.

It is considered a form of 5-alpha-reductase deficiency involving SRD5A2.

The main treatment for isolated epispadias is a comprehensive surgical repair of the genito-urinary area usually during the first 7 years of life, including reconstruction of the urethra, closure of the penile shaft and mobilisation of the corpora. The most popular and successful technique is known as the modified Cantwell-Ransley approach. In recent decades however increasing success has been achieved with the complete penile disassembly technique despite its association with greater and more serious risk of damage.

It is a rare condition, with only approximately 60 cases reported as of 1989, and 75 cases as of 2005. However, due to the stigma of intersex conditions and the issues of keeping accurate statistics and records among doctors, it is likely there are more cases than reported.

In one report, about 20% of individuals with mealtime syndrome had strictures upon sialography. For unknown reasons, strictures seem to be more common in females.

Hypospadias is among the most common birth defects in the world and is said to be the second-most common birth defect in the male reproductive system, occurring once in every 250 males.

Due to variations in the reporting requirements of different national databases, data from such registries cannot be used to accurately determine either incidence of hypospadias or geographical variations in its occurrences.

A bifid penis (or double penis) is a rare congenital defect where two genital tubercles develop.

Historically, males born with a bifid penis often underwent sex reassignment surgery, due to the difficulty of penile reconstruction. They were raised as girls, and often had reconstructive surgery to make them phenotypically female, coupled with female hormone replacement therapy. However, in recent years, this practice has fallen under heavy scrutiny due to both a high frequency of sexual dysfunction in gender converted children, and more advanced penile reconstruction techniques.

Many male marsupials naturally have a bifid penis, with left and right prongs that they insert into multiple vaginal canals simultaneously.

Aphallia has no known cause. It is not linked to deficient hormone amounts or action, but rather to a failure of the fetal genital tubercle to form between 3 and 6 weeks after conception. The urethra of an affected child opens on the perineum.

Genital prolapse occurs in about 316 million women worldwide as of 2010 (9.3% of all females).

Anal stricture or anal stenosis is a narrowing of the anal canal. It can be caused by a number of surgical procedures including: hemorrhoid removal and following anorectal wart treatment.

A pelvic fracture can cause the urethra to separate, leading to a variable length of scar that can severely hamper the ability to urinate normally. The urethra is a tubular conduit that transports urine out of the bladder. The bulbar urethra is a segment of the male urethra that is in between the penile urethra and the membrano-prostatic urethra that typically has a robust blood supply. This blood supply includes antegrade flow from the paired bulbar arteries and circumflex arteries, and retrograde flow from the paired dorsal arteries of the penis.

Bulbar urethral necrosis is a problem that can occur after a pelvic fracture associated urethral distraction defect (PFUDD).

Pelvic organ prolapse (POP) is characterized by descent of pelvic organs from their normal positions. In women, the condition usually occurs when the pelvic floor collapses after gynecological cancer treatment, childbirth or heavy lifting.

In men, it may occur after the prostrate gland is removed. The injury occurs to fascia membranes and other connective structures that can result in cystocele, rectocele or both. Treatment can involve dietary and lifestyle changes, physical therapy, or surgery.

Strictures tend to be diagnosed based on difficulty with insertion and manipulation during sialendoscopy, or by sialography or ultrasound.

There is increasing evidence that the harmful products of tobacco smoking may damage the testicles and kill sperm, but their effect on male fertility is not clear. Some governments require manufacturers to put warnings on packets. Smoking tobacco increases intake of cadmium, because the tobacco plant absorbs the metal. Cadmium, being chemically similar to zinc, may replace zinc in the DNA polymerase, which plays a critical role in sperm production. Zinc replaced by cadmium in DNA polymerase can be particularly damaging to the testes.

A male genital disease is a condition that affects the male reproductive system. An example is orchitis.

non infection disease