Left untreated, urethral diverticulum can cause significant morbidity (sickness).

During surgery, there is a risk for complications due to the highly vascular nature of the tissue. The urethral sphincters and its smooth muscle, as well as the neck of the bladder, can be injured regardless of the surgical approach. Other complications from surgery can include urinary incontinence, stress incontinence, a urethrovaginal fistula, or recurrent diverticula. Horseshoe-shaped diverticula and diverticula that completely surround the urethra are both associated with worse outcomes, as are those located close to the bladder, and large (over 3–4 cm) diverticula.

The primary treatment for urethral diverticulum is surgical. The surgery is conducted transvaginally, usually when there is no acute inflammation to better aid dissection of the delicate tissues.

Many women delay treatment for decades. Surgeons often will correct the fistula through major gynecological surgery. Newer treatments can include the placement of a stent and is usually successful. In 0.5-2.5% of major pelvic surgeries a ureterovaginal fistula will form, usually weeks later. If the fistula cannot be repaired, the clinician may create a permanent diversion of urine or urostomy. Risks associated with the repair of the fistula are also associated with most other surgical procedures and include the risk of adhesions, disorders of wound healing, infection, ileus, and immobilization. There is a recurrence rate of 5%–15% in the surgical operation done to correct the fistula.

Birth injuries that result in the formation of fistulas and urinary and fecal incontinence have been found to be strongly associated with economic and cultural factors. Teenagers and women who sustain injuries that develop into ureterovaginal fistulas during childbirth suffer significant social stigma. Ureterovaginal fistulas related to prolonged, obstructed labor are rare in developed nations but are more common in countries where access to emergent obstetrical care is limited.

There are several stages to treating an anal fistula:

Definitive treatment of a fistula aims to stop it recurring. Treatment depends on where the fistula lies, and which parts of the internal and external anal sphincters it crosses.

There are several options:

- Doing nothing — a drainage seton can be left in place long-term to prevent problems. This is the safest option although it does not definitively cure the fistula.

- Lay-open of fistula-in-ano — this option involves an operation to cut the fistula open. Once the fistula has been laid open it will be packed on a daily basis for a short period of time to ensure that the wound heals from the inside out. This option leaves behind a scar, and depending on the position of the fistula in relation to the sphincter muscle, can cause problems with incontinence. This option is not suitable for fistulae that cross the entire internal and external anal sphincter.

- Cutting seton — if the fistula is in a high position and it passes through a significant portion of the sphincter muscle, a cutting seton (from the Latin "seta", "bristle") may be used. This involves inserting a thin tube through the fistula tract and tying the ends together outside of the body. The seton is tightened over time, gradually cutting through the sphincter muscle and healing as it goes. This option minimizes scarring but can cause incontinence in a small number of cases, mainly of flatus. Once the fistula tract is in a low enough position it may be laid open to speed up the process, or the seton can remain in place until the fistula is completely cured. This was the traditional modality used by physicians in Ancient Egypt and formally codified by Hippocrates, who used horsehair and linen.

- Seton stitch — a length of suture material looped through the fistula which keeps it open and allows pus to drain out. In this situation, the seton is referred to as a draining seton. The stitch is placed close to the ano-rectal ring – which encourages healing and makes further surgery easy.

- Fistulotomy — till anorectal ring

- Colostomy — to allow healing

- Fibrin glue injection is a method explored in recent years, with variable success. It involves injecting the fistula with a biodegradable glue which should, in theory, close the fistula from the inside out, and let it heal naturally. This method is perhaps best tried before all others since, if successful, it avoids the risk of incontinence, and creates minimal stress for the patient.

- Fistula plug involves plugging the fistula with a device made from small intestinal submucosa. The fistula plug is positioned from the inside of the anus with suture. According to some sources, the success rate with this method is as high as 80%. As opposed to the staged operations, which may require multiple hospitalizations, the fistula plug procedure requires hospitalization for only about 24 hours. Currently, there are two different anal fistula plugs cleared by the FDA for treating ano-rectal fistulae in the United States. This treatment option does not carry any risk of bowel incontinence. In the systematic review published by Dr Pankaj Garg, the success rate of the fistula plug is 65-75%.

- Endorectal advancement flap is a procedure in which the internal opening of the fistula is identified and a flap of mucosal tissue is cut around the opening. The flap is lifted to expose the fistula, which is then cleaned and the internal opening is sewn shut. After cutting the end of the flap on which the internal opening was, the flap is pulled down over the sewn internal opening and sutured in place. The external opening is cleaned and sutured. Success rates are variable and high recurrence rates are directly related to previous attempts to correct the fistula.

- LIFT Technique is a novel modified approach through the intersphincteric plane for the treatment of fistula-in-ano, known as LIFT (ligation of intersphincteric fistula tract) procedure. LIFT procedure is based on secure closure of the internal opening and removal of infected cryptoglandular tissue through the intersphincteric approach. Essential steps of the procedure include, incision at the intersphincteric groove, identification of the intersphincteric tract, ligation of intersphincteric tract close to the internal opening and removal of intersphincteric tract, scraping out all granulation tissue in the rest of the fistulous tract, and suturing of the defect at the external sphincter muscle. The procedure was developed by Thai colorectal surgeon, Arun Rojanasakul, The first reports of preliminary healing result from the procedure were 94% in 2007. Additional ligation of the intersphincteric fistula tract did not improve the outcome after endorectal advancement flap.

- Fistula clip closure (OTSC Proctology) is the latest surgical development, which involves the closure of the internal fistula opening with a superelastic clip made of nitinol (OTSC). During surgery, the fistula tract is debrided with a special fistula brush and the clip is transanally applied with the aid of a preloaded clip applicator. The surgical principle of this technique relies on the dynamic compression and permanent closure of the internal fistula opening by the superelastic clip. Consequently, the fistula tract dries out and heals instead of being kept open by continuous feeding with stool and fecal organisms. This minimally-invasive sphincter-preserving technique has been developed and clinically implemented by the German surgeon Ruediger Prosst. First clinical data of the clip closure technique demonstrate a success rate of 90% for previously untreated fistulae and a success rate of 70% for recurrent fistulae.

- PERFACT Procedure is another latest addition to the armamentarium to treat complex and highly complex fistula-in-ano. It is a minimally cutting procedure as both the anal sphincters (internal and external sphincters) are not cut/damaged at all. Therefore, the risk of incontinence is minimal. PERFACT procedure (proximal superficial cauterization, emptying regularly fistula tracts and curettage of tracts) entails two steps: superficial cauterization of mucosa at and around the internal opening and keeping all the tracts clean. The principle is to permanently close the internal opening by granulation tissue. This is achieved by superficial electrocauterization at and around the internal opening and subsequently allowing the wound to heal by secondary intention. Early results of this procedure are quite encouraging for complex fistula-in-ano (86.4% in highly complex anal fistulae). The procedure is effective even in fistula associated with abscess, supralevator fistula-in-ano and fistula where the internal opening is non-localizable.

Treatment for fistula varies depending on the cause and extent of the fistula, but often involves surgical intervention combined with antibiotic therapy.

Typically the first step in treating a fistula is an examination by a doctor to determine the extent and "path" that the fistula takes through the tissue.

In some cases the fistula is temporarily covered, for example a fistula caused by cleft palate is often treated with a palatal obturator to delay the need for surgery to a more appropriate age.

Surgery is often required to assure adequate drainage of the fistula (so that pus may escape without forming an abscess). Various surgical procedures are commonly used, most commonly fistulotomy, placement of a seton (a cord that is passed through the path of the fistula to keep it open for draining), or an endorectal flap procedure (where healthy tissue is pulled over the internal side of the fistula to keep feces or other material from reinfecting the channel). Treatment involves filling the fistula with fibrin glue; also plugging it with plugs made of porcine small intestine submucosa have also been explored in recent years, with variable success. Surgery for anorectal fistulae is not without side effects, including recurrence, reinfection, and incontinence. High rate of recurrence and more chances of complications like incontinence are always there in fistula surgeries (Anal Fistula).

It is important to note that surgical treatment of a fistula without diagnosis or management of the underlying condition, if any, is not recommended. For example, surgical treatment of fistulae in Crohn's disease can be effective, but if the Crohn's disease itself is not treated, the rate of recurrence of fistula is very high (well above 50%).

Some people will have an active infection when they present with a fistula, and this requires clearing up before definitive treatment can be decided.

Antibiotics can be used as with other infections, but the best way of healing infection is to prevent the buildup of pus in the fistula, which leads to abscess formation. This can be done with a seton.

After diagnosing rectovaginal fistula, it is best to wait for around 3 months to allow the inflammation to subside. For low fistulae, a vaginal approach is best, while an abdominal repair would be necessary for a high fistula at the posterior fornix.

A circular incision is made around the fistula and vagina is separated from the underlying rectum with a sharp circumferential dissection. The entire fistulous tract, along with a small rim of rectal mucosa is incised. The rectal wall is then closed extramucosally.

Most rectovaginal fistuals will need surgery to fix. Medications such as antibiotics and Infliximab might be prescribed to help close the rectovaginal fistula or prepare for surgery.

In people with renal failure, requiring dialysis, a cimino fistula is often deliberately created in the arm by means of a short day surgery in order to permit easier withdrawal of blood for hemodialysis.

As a radical treatment for portal hypertension, surgical creation of a portacaval fistula produces an anastomosis between the hepatic portal vein and the inferior vena cava across the omental foramen (of Winslow). This spares the portal venous system from high pressure which can cause esophageal varices, caput medusae, and hemorrhoids.

Rectovestibular fistula is the most common defect of the rectum and anal canal in females.

Vesicovaginal fistulae are typically repaired either transvaginally or laparoscopically, although patients who have had multiple transvaginal procedures sometimes attempt a final repair through a large abdominal incision, or laparotomy.

The laparoscopic (minimally invasive) approach to VVF repair has become more prevalent due to its greater visualization, higher success rate, and lower rate of complications.

A meta-analysis on the influence of voiding position on urodynamics in healthy males and males with LUTS showed that in the sitting position, the residual urine in the bladder was significantly reduced. The other parameters, namely the maximum urinary flow and the voiding time were increased and decreased respectively. For healthy males, no influence was found on these parameters, meaning that they can urinate in either position.

Urinary tract obstruction as a congenital disorder results in oligohydramnios which in turn can lead to the Potter sequence of atypical physical appearance. Pulmonary hypoplasia is by far the main cause of death in the early neonatal period for children with congenital lower urinary tract obstruction.

Fetal surgery of congenital lower urinary tract obstruction seems to improve survival, according to a randomized yet small study.

Rectovaginal fistulas are often the result of trauma during childbirth (in which case it is known as obstetric fistula) where improper medical interventions are used, such as episiotomy with forceps/vacuum extraction or in situations where there is inadequate health care, such as in some developing countries. Rectovaginal fistula is said to be known as the leading cause in maternal death in developing countries. Risk factors include prolonged labour, difficult instrumental delivery and paramedian episiotomy. Rates in Eritrea are estimated as high as 350 per 100,000 vaginal births. Fistulas can also develop as a result of physical trauma to either the vagina or anus, including from rape. Women with rectovaginal fistulae are often stigmatized in developing countries, and become outcasts.

Rectovaginal fistula can also be a symptom of various diseases, including infection by lymphogranuloma venereum, or the unintended result of surgery, such as episiotomy or sexual reassignment surgery. They may present as a complication of vaginal surgery, including vaginal hysterectomy. They are a recognized presentation of rectal carcinoma or rarely diverticular disease of the bowel or Crohn's disease. They are seen rarely after radiotherapy treatment for cervical cancer.

Colostomy is recommended by most surgeons, and has a good prognosis, with 90% of patients regaining normal bowel control. Since the rectal opening and anal orifice in a vestibular fistula tend to be short and narrow, a colostomy is usually performed to allow decompression of the bowel unless the orifice is wide enough to allow normal defecation. Colostomy is often followed by posterior sagittal anorectoplasty (PSARP), a surgical procedure to repair the anal orifice, at a later date. Some surgeons prefer to perform an immediate PSARP without a colostomy first, while others perform neither a colostomy nor a PSARP and instead opt for a simple dilatation of the orifice to allow stool to pass and the bowel to decompress. It has been suggested that only experienced surgeons should perform repair without an initial colostomy.

It is often caused by childbirth (in which case it is known as an obstetric fistula), when a prolonged labor presses the unborn child tightly against the pelvis, cutting off blood flow to the vesicovaginal wall. The affected tissue may necrotize (die), leaving a hole.

Vaginal fistulas can also result from particularly violent cases of rape, especially those involving multiple rapists and/or foreign objects. Some health centers in countries such as the Democratic Republic of Congo have begun to specialize in the surgical repair of vaginal fistulas.

It can also be associated with hysterectomy, cancer operations, radiation therapy and cone biopsy.

A biliary fistula is a type of fistula in which bile flows along an abnormal connection from the bile ducts into nearby hollow structure. Types of biliary fistula include:

- bilioenteric fistula: abnormal connection to small bowel, usually duodenum.

- thoracobiliary fistula: abnormal connection to pleural space or bronchus (rare).

These may be contrasted to a bile leak, in which bile escapes the bile ducts through a perforation or faulty surgical anastomosis into the abdominal cavity. Damage to a bile duct may result in a leak, which may eventually become a biliary fistula.

A fistula involving the bladder can have one of many specific names, describing the specific location of its outlet:

- Bladder and intestine: "vesicoenteric", "enterovesical", or "vesicointestinal"

- Bladder and colon: "vesicocolic" or "colovesical"

- Bladder and rectum: "vesicorectal" or "rectovesical"

It is surgically corrected, with resection of any fistula and anastomosis of any discontinuous segments.

Neonates with TEF or esophageal atresia are unable to feed properly. Once diagnosed, prompt surgery is required to allow the food intake. Some children do experience problems following TEF surgery; they can develop dysphagia and thoracic problems. Children with TEF can also be born with other abnormalities, most commonly those described in VACTERL association - a group of anomalies which often occur together, including heart, kidney and limb deformities. 6% of babies with TEF also have a laryngeal cleft.

Many causes exist including:

- diverticulitis : most common ~ 60%

- colorectal cancer (CRC) : ~ 20%

- Crohn's disease : ~ 10%

- radiotherapy

- appendicitis

- trauma

With a high lesion, many children have problems controlling bowel function and most also become constipated. With a low lesion, children generally have good bowel control, but they may still become constipated.

For children who have a poor outcome for continence and constipation from the initial surgery, further surgery to better establish the angle between the anus and the rectum may improve continence and, for those with a large rectum, surgery to remove that dilated segment may significantly improve the bowel control for the patient. An antegrade enema mechanism can be established by joining the appendix to the skin (Malone stoma); however, establishing more normal anatomy is the priority.

It can occur as a complication following biliary trauma (such as cholelithiasis), as an iatrogenic effect or as a result of a penetrating injury.

Treatments range from recommendations for over-the-counter products to more invasive surgical procedures.

Among the most common outpatient advice given to patients with less severe disorders include a high-fiber diet, application of ointment, and increased water intake. More serious procedures include the removal of affected tissue, injection of botulinum toxin, or surgically opening the fistula tract in the sphincter muscle.

Hydrocolpos is the distension of the vagina caused by accumulation of fluid due to congenital vaginal obstruction. The obstruction is often caused by an imperforate hymen or less commonly a transverse vaginal septum. The fluid consists of cervical and endometrial mucus or in rare instances urine accumulated through a vesicovaginal fistula proximal to the obstruction. In some cases it is associated with Bardet-Biedl Syndrome. If it occurs in prepubertal girls, it may show up as abdominal swelling. It may be detected by using ultrasound. It may also present at birth as a distended lower abdomen and vagina. It also associated with vaginal atresia.