A perineal tear is a laceration of the skin and other soft tissue structures which, in women, separate the vagina from the anus. Perineal tears mainly occur in women as a result of vaginal childbirth, which strains the perineum. Tears vary widely in severity. The majority are superficial and require no treatment, but severe tears can cause significant bleeding, long-term pain or dysfunction. A perineal tear is distinct from an episiotomy, in which the perineum is intentionally incised to facilitate delivery.

Tears are classified into four categories:

- First-degree tear: laceration is limited to the fourchette and superficial perineal skin or vaginal mucosa

- Second-degree tear: laceration extends beyond fourchette, perineal skin and vaginal mucosa to perineal muscles and fascia, but not the anal sphincter

- Third-degree tear: fourchette, perineal skin, vaginal mucosa, muscles, and anal sphincter are torn; third-degree tears may be further subdivided into three subcategories:

- 3a: partial tear of the external anal sphincter involving less than 50% thickness

- 3b: greater than 50% tear of the external anal sphincter

- 3c: internal sphincter is torn

- Fourth-degree tear: fourchette, perineal skin, vaginal mucosa, muscles, anal sphincter, and rectal mucosa are torn

Abnormal descent of the perineum may be asymptomatic, but otherwise the following may feature:

- perineodynia (perineal pain)

- Colo-proctological symptoms, e.g. obstructed defecation, dyschesia (constipation), or degrees of fecal incontinence

- gynaecological symptoms, e.g. cystocele (prolapse of the bladder into the vagina) and rectocele (prolapse of the rectum into the vagina)

- lower urinary tract symptoms, e.g. dysuria (painful urination), dyspareunia (pain during sexual intercourse), urinary incontinence & urgency

Other researchers concluded that abnormal perineal descent did not correlate with constipation or perineal pain, and there are also conflicting reports of the correlation of fecal incontinence with this condition.

The hallmark sign of urethral stricture is a weak urinary stream. Other symptoms include:

- Splaying of the urinary stream

- Urinary frequency

- Urinary urgency

- Straining to urinate

- Pain during urination

- Urinary tract infection

- Prostatitis

- Inability to completely empty the bladder.

Some patients with severe urethral strictures are completely unable to urinate. This is referred to as acute urinary retention, and is a medical emergency. Hydronephrosis and renal failure may also occur.

A urethral stricture is a narrowing of the urethra caused by injury, instrumentation, infection and certain non-infectious forms of urethritis.

Descending perineum syndrome (also known as Levator plate sagging) refers to a condition where the perineum "balloons" several centimeters below the bony outlet of the pelvis during strain, although this descent may happen without straining. The syndrome was first described in 1966 by Parks "et al".

Post-void dribbling or post-micturition dribbling is the where urine remaining in the urethra after voiding the bladder slowly leaks out after urination. A common and usually benign complaint, it may be a symptom of urethral diverticulum, prostatitis and other medical problems.

Men who experience dribbling, especially after prostate cancer surgery, will choose to wear incontinence pads to stay dry. Also known as guards for men, these incontinence pads conform to the male body. Some of the most popular male guards are from Tena, Depends, and Prevail. Simple ways to prevent dribbling include: strengthening pelvic muscles with Kegel exercises, changing position while urinating, or pressing on the perineum to evacuate the remaining urine from the urethra. Sitting down while urinating is also shown to alleviate complaints: a meta-analysis on the effects of voiding position in elderly males with benign prostate hyperplasia found an improvement of urologic parameters in this position, while in healthy males no such influence was found.

Perineal hernia is a hernia involving the perineum (pelvic floor). The hernia may contain fluid, fat, any part of the intestine, the rectum, or the bladder. It is known to occur in humans, dogs, and other mammals, and often appears as a sudden swelling to one side (sometimes both sides) of the anus.

A common cause of perineal hernia is surgery involving the perineum. Perineal hernia can be caused also by excessive straining to defecate (tenesmus). Other causes include prostate or urinary disease, constipation, anal sac disease (in dogs), and diarrhea. Atrophy of the levator ani muscle and disease of the pudendal nerve may also contribute to a perineal hernia.

Bloody show is the passage of a small amount of blood or blood-tinged mucus through the vagina near the end of pregnancy. It can occur just before labor or in early labor as the cervix changes shape, freeing mucus and blood that occupied the cervical glands or cervical os. Bloody show is a relatively common feature of pregnancy, and it does not signify increased risk to the mother or baby . A larger amount of bleeding, however, may signify a more dangerous, abnormal complication of pregnancy, such as placental abruption or placenta previa. Large amounts of bleeding during or after childbirth itself may come from uterine atony or laceration of the cervix, vagina, or perineum.

Three common signs of the onset of labor are:

1. A bloody show

2. Rupture of membranes ("Water breaking")

3. Onset of tightenings or contractions

However, these may occur at any time and in any order. Some women neither experience a bloody show nor have their "water break" until well into advanced labor. Therefore, neither bloody show nor rupture of membranes are required to establish labor.

Obstructed defecation is one of the causes of chronic constipation. Obstructed defecation could be considered to be a type of bowel obstruction, where it may be classified under large bowel obstruction. Obstructed defecation frequently gives rise to a symptom called tenesmus. Constipation, bowel obstruction and tenesmus are therefore all closely related topics.

Outlet obstruction can be classified into 4 groups.

- Functional outlet obstruction

- Mechanical outlet obstruction

- Dissipation of force vector

- Impaired rectal sensitivity

In humans, a major cause of perineal hernia is perineal surgery without adequate reconstruction. In some cases, particularly surgeries to remove the coccyx and distal sacrum, adequate reconstruction is very difficult to achieve. The posterior perineum is a preferred point of access for surgery in the pelvic cavity, particularly in the presacral space. Surgeries here include repair of rectal prolapse and anterior meningocele, radical perineal prostatectomy, removal of tumors including sacrococcygeal teratoma, and coccygectomy. Perineal hernia is a common complication of coccygectomy in adults, but not in infants and children (see coccygectomy).

The standard surgical technique for repair of perineal hernia uses a prosthetic mesh, but this technique has a high rate of failure due to insufficient anchoring. Promising new techniques to reduce the rate of failure include an orthopedic anchoring system, a gluteus maximus muscle flap, an acellular human dermis graft, and an acellular pig collagen graft.

Fecal incontinence to gas, liquid, solid stool, or mucus in the presence of obstructed defecation symptoms may indicate occult rectal prolapse (i.e. rectal intussusception), internal/external anal sphincter dysfunction, or descending perineum syndrome.

The main causes of obstructed labour include: a large or abnormally positioned baby, a small pelvis, and problems with the birth canal. Abnormal positioning includes shoulder dystocia where the anterior shoulder does not pass easily below the pubic bone. Risk factors for a small pelvis include malnutrition and a lack of exposure to sunlight causing vitamin D deficiency. while problems with the birth canal include a narrow vagina and perineum which may be due to female genital mutilation or tumors.

Obstructed labour, also known as labour dystocia, is when, even though the uterus is contracting normally, the baby does not exit the pelvis during childbirth due to being physically blocked. Complications for the baby include not getting enough oxygen which may result in death. It increases the risk of the mother getting an infection, having uterine rupture, or having post-partum bleeding. Long term complications for the mother include obstetrical fistula. Obstructed labour is said to result in prolonged labour, when the active phase of labour is longer than twelve hours.

The main causes of obstructed labour include: a large or abnormally positioned baby, a small pelvis, and problems with the birth canal. Abnormal positioning includes shoulder dystocia where the anterior shoulder does not pass easily below the pubic bone. Risk factors for a small pelvis include malnutrition and a lack of exposure to sunlight causing vitamin D deficiency. It is also more common in adolescence as the pelvis may not have finished growing. Problems with the birth canal include a narrow vagina and perineum which may be due to female genital mutilation or tumors. A partograph is often used to track labour progression and diagnose problems. This combined with physical examination may identify obstructed labour.

The treatment of obstructed labour may require cesarean section or vacuum extraction with possible surgical opening of the symphysis pubis. Other measures include: keeping the women hydrated and antibiotics if the membranes have been ruptured for more than 18 hours. In Africa and Asia obstructed labor affects between two and five percent of deliveries. In 2015 about 6.5 million cases of obstructed labour or uterine rupture occurred. This resulted in 23,000 maternal deaths down from 29,000 deaths in 1990 (about 8% of all deaths related to pregnancy). It is also one of the leading causes of stillbirth. Most deaths due to this condition occur in the developing world.

Odynorgasmia, or painful ejaculation, is a physical syndrome described by pain or burning sensation of the urethra or perineum during or following ejaculation. Causes include infections associated with urethritis, prostatitis, epididymitis, as well as use of anti-depressants.

Many other less common conditions can lead to testicular pain. These include inguinal hernias, injury, hydroceles, and varicoceles among others. Testicular cancer is usually painless. Another potential cause is epididymal hypertension (also known as "blue balls").

Fournier's gangrene ( an aggressive and rapidly spreading infection of the perineum ) usually presents with fever and intense pain. It is a rare condition but fatal if not identified and aggressively treated with a combination of surgical debridement and broad spectrum antibiotics.

Retrograde ejaculation occurs when semen, which would, in most cases, be ejaculated via the urethra, is redirected to the urinary bladder. Normally, the sphincter of the bladder contracts before ejaculation forcing the semen to exit via the urethra, the path of least resistance. When the bladder sphincter does not function properly, retrograde ejaculation may occur. It can also be induced deliberately by a male as a primitive form of male birth control (known as "coitus saxonicus") or as part of certain alternative medicine practices.

Most cases involve a small and bifid penis, which requires surgical closure soon after birth, often including a reconstruction of the urethra. Where it is part of a larger exstrophy, not only the urethra but also the bladder (bladder exstrophy) or the entire perineum (cloacal exstrophy) are open and exposed on birth, requiring closure.

Despite the similarity of name, an epispadias is not a type of hypospadias, and involves a problem with a different set of embryologic processes.

Women can also have this type of congenital malformation. Epispadias of the female may occur when the urethra develops too far anteriorly, exiting in the clitoris or even more forward. For females, this may not cause difficulty in urination but may cause problems with sexual satisfaction. Frequently, the clitoris is bifurcated at the site of urethral exit, and therefore clitoral sensation is less intense during sexual intercourse due to frequent stimulation during urination. However, with proper stimulation, using either manual or positional techniques, clitoral orgasm is definitely possible.

PPSH usually consists of:

- a phallus midway in size between penis and clitoris,

- a chordee tethering it to the perineum,

- a urethral opening usually on the perineum (the hypospadias),

- and an incompletely closed urogenital opening, which resembles a small and shallow vagina.

Testes are often palpable in the scrotum or inguinal canals, and the karyotype is XY. In most cases there are no internal female structures such as a uterus or other Müllerian duct derivatives.

Mallory–Weiss syndrome or gastro-esophageal laceration syndrome refers to bleeding from a laceration in the mucosa at the junction of the stomach and esophagus. This is usually caused by severe vomiting because of alcoholism or bulimia, but can be caused by any conditions which causes violent vomiting and retching such as food poisoning. The syndrome presents with hematemesis. The laceration is sometimes referred to as a "Mallory-Weiss tear".

There are several forms of imperforate anus and anorectal malformations. The new classification is in relation of the type of associated fistula.

The classical Wingspread classification was in low and high anomalies:

- A low lesion, in which the colon remains close to the skin. In this case, there may be a stenosis (narrowing) of the anus, or the anus may be missing altogether, with the rectum ending in a blind pouch.

- A high lesion, in which the colon is higher up in the pelvis and there is a fistula connecting the rectum and the bladder, urethra or the vagina.

- A persistent cloaca (from the term cloaca, an analogous orifice in reptiles and amphibians), in which the rectum, vagina and urinary tract are joined into a single channel.

Imperforate anus is usually present along with other birth defects—spinal problems, heart problems, tracheoesophageal fistula, esophageal atresia, renal anomalies, and limb anomalies are among the possibilities.

A malfunctioning bladder sphincter, leading to retrograde ejaculation, may be a result either of:

- Autonomic nervous system dysfunction. (Dysautonomia)

- Operation on the prostate. It is a common complication of transurethral resection of the prostate, a procedure in which prostate tissue is removed, slice by slice, through a resectoscope passed along the urethra.

It can also be caused by a retroperitoneal lymph node dissection for testicular cancer if nerve pathways to the bladder sphincter are damaged, with the resulting retrograde ejaculation being either temporary or permanent. Modern nerve-sparing techniques seek to reduce this risk; however, it may also occur as the result of Green Light Laser prostate surgery.

Surgery on the bladder neck accounted for about ten percent of the cases of retrograde ejaculation or anejaculation reported in a literature review.

Retrograde ejaculation is a common side effect of medications, such as tamsulosin, that are used to relax the muscles of the urinary tract, treating conditions such as benign prostatic hyperplasia. By relaxing the bladder sphincter muscle, the likelihood of retrograde ejaculation is increased.

The medications that mostly cause it are antidepressant and antipsychotic medication, as well as NRIs such as atomoxetine; patients experiencing this phenomenon tend to quit the medications.

Retrograde ejaculation can also be a complication of diabetes, especially in cases of diabetics with long term poor blood sugar control. This is due to neuropathy of the bladder sphincter. Post-pubertal males (aged 17 to 20 years) who experience repeated episodes of retrograde ejaculation are often diagnosed with urethral stricture disease shortly after the initial complaint arises. It is currently not known whether a congenital malformation of the bulbous urethra is responsible, or if pressure applied to the base of the penis or perineum immediately preceding ejaculatory inevitability may have inadvertently damaged the urethra. This damage is most often seen within 0.5 cm of the ejaculatory duct (usually distal to the duct).

Retrograde ejaculation can also result from pinching closed the urethral opening, to avoid creating a mess upon ejaculation (known as "Hughes' technique").

There are other forms of anorectal malformations though imperforate anus is most common. Other variants include anterior ectopic anus. This form is more commonly seen in females and presents with constipation.