Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Obstetric fistula and post-surgical urinary injury
Obstetrics and gynaecology · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Suspected urinary-tract injury, obstruction or infected leak
Anuria or oliguria, rising creatinine, severe flank or abdominal pain, peritonism, fever or sepsis, ileus, expanding urinoma, haemodynamic instability or high-output clear fluid from a drain or vagina after pelvic surgery can indicate bladder or ureteric injury with obstruction or uncontrolled urine leakage.
Action: Assess observations, sepsis, abdomen, urine output, renal function and operative details immediately; involve senior gynaecology and urology, obtain urgent anatomy-directed imaging, give sepsis treatment when indicated, and establish bladder, ureteric or percutaneous drainage without waiting for a routine fistula appointment.
Overview
Recognise urinary or bowel fistula and iatrogenic bladder or ureteric injury early, select anatomy-specific investigations, stabilise acute harm and arrange reconstructive specialist care without stigma or avoidable delay.
A urogenital fistula is an abnormal communication through which urine bypasses its normal route. Vesicovaginal fistula connects bladder to vagina, ureterovaginal fistula connects a ureter to vagina and urethrovaginal fistula involves the urethra. A rectovaginal fistula transmits flatus or faeces rather than urine. Precise anatomy matters because the investigation, drainage and reconstruction are different; the umbrella label 'incontinence' is not an adequate diagnosis.
Globally, classic obstetric fistula is a preventable childbirth injury associated with prolonged obstructed labour and lack of timely emergency obstetric care. The presenting person may have survived stillbirth, major pelvic-tissue damage and profound social exclusion. Sustained compression between the fetal presenting part and maternal pelvis interrupts perfusion; devitalised tissue separates over subsequent days, so leakage may begin after the birth rather than during it. The consultation should explicitly reject blame and provide privacy, dignity and psychosocial support.
Practice
Two practice questions
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Obstetrics and gynaecologyOriginal SBA
Recognising obstetric fistula
A woman reports continuous urine leakage since surviving prolonged obstructed labour in a setting where emergency obstetric care was delayed. Painful skin irritation and social isolation have followed. What is the most appropriate interpretation and response?
Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 27 Aug 2026; clinical approval remains outstanding.
In a well-resourced UK setting, a new urinary fistula more commonly follows pelvic surgery or malignancy treatment than neglected obstructed labour, although clinicians must remain competent to care for migrants and survivors with obstetric injury. Hysterectomy, caesarean birth, difficult prolapse or endometriosis surgery and pelvic cancer surgery can injure bladder or ureter by transection, ligation, devascularisation, crush or thermal damage. Radiotherapy produces fibrotic, poorly vascular tissue; cancer recurrence and Crohn's disease require disease control as well as reconstruction.
Presentation depends on level and timing. Vesicovaginal fistula usually causes continuous vaginal wetness with urine odour and little relationship to cough or urgency. A ureterovaginal fistula may allow normal voiding from the unaffected kidney while urine also leaks continuously through the vagina; flank pain, fever, hydronephrosis or a urinoma strengthens concern for ureteric injury. Early bladder injury may instead produce haematuria, suprapubic pain, low urine output, abdominal distension, peritonitis, ileus or urine through a surgical drain.
The history reconstructs the event: exact operation, date, difficult dissection, energy use, intraoperative cystoscopy or repair, postoperative urine output, catheter course, onset and pattern of wetness, flank or abdominal symptoms, infection and previous radiotherapy. Ask sensitively about birth trauma, faecal leakage, menstrual passage, sex, fertility, skin injury and effect on work, relationships and mental health. Obtain the operation note and imaging rather than asking the patient to repeatedly prove what happened.
Examination begins with stability, abdomen, drains, renal angles and skin. With consent, trauma-informed speculum examination may identify urine pooling, the tract, tissue necrosis, vaginal scarring, mesh or malignancy. A bladder dye test with a vaginal swab or tampon can support vesicovaginal communication; clear ongoing fluid without bladder dye raises ureterovaginal leakage. Fluid creatinine substantially above serum supports urine, but neither bedside test maps the ureter or excludes multiple fistulae.
Imaging is selected for the suspected organ. Current European urological-trauma guidance identifies CT urography with a delayed phase as the examination of choice for suspected ureteric injury. Extravasation is diagnostic, while hydronephrosis, urinoma, ascites or mild ureteric dilatation may be the only clue. Retrograde or antegrade urography best confirms uncertain anatomy and can lead directly to stenting or nephrostomy. For suspected bladder rupture, active retrograde cystography with adequate filling is required; routine passive excretory filling can miss the defect.
Management separates immediate physiological control from definitive repair. Resuscitate sepsis, treat culture-guided infection, relieve obstruction and drain infected or enlarging collections. An injury recognised during surgery should usually be assessed and repaired immediately by an appropriately experienced team when the patient and setting allow. Delayed ureteric injury is initially diverted with percutaneous nephrostomy or a JJ stent where feasible, preserving renal function while inflammation settles and reconstructive planning is completed.
Some very small, recently formed vesicovaginal fistulae may close with continuous bladder drainage, but this is a specialist selection rather than a promise or a reason to postpone referral. Definitive vaginal, abdominal, laparoscopic or robotic repair is individualised to site, size, tissue quality, ureteric involvement, prior radiation, previous attempts and patient preference. A catheter commonly remains for weeks after repair. Timing is based on infection control, tissue condition and expertise rather than one universal waiting interval.
Recovery is multidimensional. Protect macerated skin, optimise nutrition and anaemia, address pain and infection, provide continence products without making them the endpoint, and offer sexual, fertility and future-pregnancy counselling. Obstetric-fistula survivors may need physiotherapy, social support and sensitive mental-health care. Follow-up confirms closure, unobstructed renal drainage, bladder emptying and a plan for recurrent leakage; successful anatomical closure does not erase the experience or guarantee normal bladder function.
Key points
Obstetric fistula most often follows prolonged obstructed labour without timely operative birth: sustained pressure causes ischaemic pelvic-tissue necrosis and a delayed opening into bladder, ureter, urethra or rectum.
In UK practice, gynaecological or obstetric surgery is a major setting for new urinary fistula or ureteric injury; malignancy, radiotherapy, inflammatory disease and trauma are other causes.
Continuous vaginal urine leakage suggests fistula rather than stress or urgency incontinence; preserved normal urethral voiding alongside continuous leakage particularly suggests ureterovaginal communication.
Absence of haematuria does not exclude ureteric injury, and thermal or ischaemic injury may present days after an apparently uncomplicated operation.
For suspected ureteric injury in a stable patient, CT urography including delayed excretory images is the key anatomical study; retrograde or antegrade urography can confirm an equivocal case and permit drainage.
Suspected postoperative bladder injury is assessed with active retrograde cystography; passive bladder filling during excretory CT is not an adequate cystogram.
A newly recognised injury may be repaired immediately by an experienced team; delayed ureteric injury commonly needs nephrostomy or JJ-stent diversion before anatomy-specific reconstruction.
Aetiology
01
Obstructed labour
Prolonged compression without timely delivery causes ischaemic necrosis between the birth canal and urinary tract or rectum.
02
Iatrogenic pelvic injury
Transection, ligation, devascularisation, crush or thermal injury during obstetric, gynaecological, colorectal or urological surgery can create leakage or delayed fistula.
03
Diseased or irradiated tissue
Pelvic malignancy, radiotherapy, Crohn's disease, infection and trauma can erode normal organ boundaries and substantially impair subsequent tissue healing.
Pathophysiology
1
Pressure-necrosis separation
Devitalised tissue sloughs after the obstructed birth, explaining why continuous leakage may begin several days later.
2
Obstruction and extravasation
A divided or ligated ureter raises upstream pressure, producing hydronephrosis, renal dysfunction and urine leakage into retroperitoneum, peritoneum or vagina.
3
Epithelialised tract
Persistent urine or enteric flow maintains an abnormal channel whose closure depends on drainage, vascular tissue and control of infection or malignancy.
Clinical features and red flags
Vesicovaginal fistula
Continuous vaginal urine loss usually dominates, often beginning after tissue separation following birth or pelvic surgery; urethral voiding may be reduced but can persist.
Ureterovaginal fistula
Continuous vaginal leakage with preserved ordinary voiding, particularly after hysterectomy or pelvic dissection, suggests urine from one ureter bypassing the bladder.
Delayed ureteric injury
Flank pain, fever, ileus, renal impairment, hydronephrosis, urinoma or vaginal or drain leakage may emerge days after ligation, devascularisation or thermal injury.
Rectovaginal fistula
Passage of flatus, faeces or offensive enteric discharge through the vagina points to bowel communication and requires colorectal as well as gynaecological assessment.
Obstetric tissue-injury complex
Pressure necrosis can coexist with vaginal stenosis, foot drop, pelvic-floor injury, infection, infertility, amenorrhoea, bereavement and severe psychosocial harm.
Red flags requiring action
No urine or markedly reduced urine after pelvic or obstetric surgery, especially with flank pain or rising creatinine.
Fever, rigors, hypotension, peritonism, ileus or a painful collection with a suspected urinary leak.
Continuous clear vaginal or drain fluid soon after hysterectomy, caesarean birth or other pelvic surgery.
New hydronephrosis, urinoma, ascites, renal impairment or contrast extravasation after an operation.
Investigations
01Urinalysis, urine culture, FBC, CRP, U&E and creatinineFirst step
Why
Assess infection, inflammation, renal injury and physiological impact before contrast, drainage or repair.
Interpretation and limitations
Treat sepsis promptly and trend renal function; a normal urinalysis does not exclude a sterile fistula or obstructed ureter.
02Vaginal-fluid creatinine and bladder dye test
Why
Confirm that clear fluid is urine and test whether it communicates with the bladder.
Interpretation and limitations
Fluid creatinine above serum supports urine; bladder dye on the vaginal swab supports vesicovaginal fistula, while persistent clear wetness without dye suggests a ureteric source but needs imaging.
03Cystoscopy with examination under anaesthesia
Why
Locate bladder and urethral openings, assess trigones and ureteric orifices, tissue quality, foreign material and malignancy, and facilitate retrograde study.
Interpretation and limitations
A visible bladder defect defines local anatomy but does not by itself exclude a second ureteric injury or bowel communication.
04CT urography with delayed excretory phase
Why
Identify ureteric discontinuity, extravasation, obstruction, hydronephrosis, urinoma and the functional upper tract.
Interpretation and limitations
Contrast leak is diagnostic; secondary findings still require urgent urological discussion, and an inadequately delayed study can miss the injury.
Differential diagnosis
01
Stress or urgency incontinence
These syndromes cause episodic urethral leakage linked to exertion or urgency rather than continuous vaginal wetness between ordinary voids.
02
Urinary retention with overflow
A high residual and palpable bladder can cause constant dribbling but does not create vaginal pooling from a tract.
03
Vaginal discharge or wound seroma
Appearance, fluid creatinine, dye testing and culture distinguish non-urinary postoperative fluid while preserving suspicion when tests are equivocal.
04
Ectopic ureter or urethral diverticulum
Congenital continuous leakage and post-void dribble have different chronology but may require reconstructive imaging when the history is longstanding.
Management
01Acute deteriorationStabilise and control the leakFirst stepPostoperative oliguria, sepsis, peritonism, obstruction, urinoma or high-output urinary drainage is suspected.+
1EscalationEscalate to senior gynaecology and urology, assess ABC physiology, sepsis, abdomen, urine output, renal function, haemoglobin and operative details.
2Start resuscitation and indicated sepsis treatment, maintain accurate fluid balance and obtain urgent CT urography or active cystography according to the suspected organ.
3Drain the bladder, obstructed upper tract and infected or enlarging collection promptly; do not defer physiological control while the final reconstructive approach is debated.
02Persistent vaginal wetnessLocalise the sourceContinuous leakage follows childbirth, pelvic surgery, radiotherapy or pelvic disease.+
Complications
01
Sepsis and collection
Urine or enteric contamination can form a painful urinoma or abscess and progress to peritonitis and life-threatening systemic sepsis.
02
Renal damage
Unrelieved ureteric obstruction, persistent extravasation or recurrent ascending infection can cause irreversible loss of ipsilateral renal function.
03
Skin and genital injury
Continuous urine or faecal exposure causes painful skin maceration, ulceration, secondary infection, odour and progressive genital tissue injury.
04
Persistent functional morbidity
Even after closure, reduced bladder capacity, urgency, stress leakage, voiding dysfunction, dyspareunia and recurrence can remain.
05
Psychosocial and reproductive harm
Isolation, trauma, depression, relationship loss, infertility, stillbirth bereavement and fear of future pregnancy require active support.
Monitoring and follow-up
In acute injury, chart urine and drain output, observations, renal function, inflammatory markers and collection size until drainage and sepsis are controlled.
After ureteric diversion or reconstruction, confirm unobstructed upper-tract drainage and monitor creatinine, infection and device complications on the specialist schedule.
During catheter treatment or after fistula repair, monitor blockage, bypassing, pain, fever and haematuria and provide a clear emergency contact route.
Inspect and protect vulval and perineal skin, and review nutrition, anaemia, mobility, pelvic-floor function and pain rather than recording continence alone.
At follow-up, ask directly and sensitively about recurrent leakage, voiding, bowel symptoms, sexual health, fertility goals, trauma symptoms, mood and social reintegration.
Special situations
Normal voiding can coexist with a fistula
One normally draining kidney can fill the bladder while the other ureter leaks into the vagina, making preserved urethral voiding a clue rather than reassurance.
Thermal injury declares itself late
A ureter that looked intact at surgery can devascularise and leak or obstruct days later, so timing does not exclude iatrogenic harm.
No haematuria is not clearance
Ureteric injury often occurs without visible blood; symptoms, operation and delayed-phase imaging carry more diagnostic weight.
Cystography must fill the bladder
Passive excreted contrast may not generate enough pressure to reveal a bladder defect; active retrograde filling is the appropriate exclusion test.
Closure is not the whole outcome
Renal preservation, skin healing, bladder function, sexuality, fertility, dignity and social recovery all belong in the definition of success.
Common pitfalls
01
Labelling continuous postoperative wetness as stress incontinence and prescribing pelvic-floor exercises without localisation.
02
Excluding ureteric injury because there is no haematuria or because urine still passes normally through the urethra.
03
Ordering a routine portal-venous CT without delayed excretory imaging when a ureteric leak is suspected.
04
Using passive excretory bladder filling as a negative cystogram or relying on one dye test to map complex anatomy.
05
Delaying drainage of an obstructed infected kidney or urinoma while waiting for elective definitive repair.
06
Promising spontaneous closure or a fixed repair date without specialist assessment of size, tissue, radiation, infection and prior attempts.
07
Reducing obstetric fistula to a surgical hole and overlooking bereavement, stigma, skin injury, malnutrition and mental health.
Fistula care includes skin, infection, renal, nutritional, sexual, reproductive and psychological assessment, not closure of a tract alone.
Faeces or gas passing through the vagina, severe perineal wound breakdown or concern for bowel injury.
Haematuria, inability to void or a painful distended bladder after difficult pelvic dissection or instrumentation.
Known pelvic malignancy, prior radiotherapy or recurrent inflammatory bowel disease with a new fistula symptom.
Tissue necrosis, offensive discharge, severe skin injury, malnutrition, safeguarding concern or marked psychological distress.
05Retrograde or antegrade urography
Why
Confirm the level and length of ureteric injury when CT is equivocal and provide access for stent or nephrostomy planning.
Interpretation and limitations
Failure of contrast to traverse the lesion or direct extravasation maps the defect; the route is chosen with reconstructive urology and interventional radiology.
06Active retrograde cystography
Why
Evaluate suspected bladder perforation or rupture with adequate controlled bladder filling.
Interpretation and limitations
Extravasation defines bladder leakage; passive filling from excreted intravenous contrast is insufficient to exclude injury.
1
Take a precise onset and voiding history, review the operation or birth record, and distinguish urine from discharge or enteric material.
2Perform a consented skin and speculum examination, urine testing and appropriately interpreted dye or fluid-creatinine testing.
3Map suspected bladder, urethral, ureteric or bowel involvement with cystoscopy, CT urography and targeted contrast or bowel investigation through the specialist team.
03Delayed ureteric injuryPreserve renal function before reconstructionImaging or urography shows obstruction or leakage from a ureter diagnosed after the original operation.+
1Discuss urgently with reconstructive urology and interventional radiology and establish drainage by nephrostomy or JJ stent when feasible.
2Treat infection, drain urinoma, document renal function and define injury level, length, tissue viability and contralateral function.
3Plan reimplantation, ureteroureterostomy or another anatomy-specific reconstruction with timing based on physiology, tissue and expertise.
04Fistula recoveryRepair anatomy and restore healthDefinitiveThe leak is controlled and definitive care is being planned.+
1Refer to a specialist urinary-fistula or reconstructive pelvic service and discuss catheter diversion, repair routes, success limits, recurrence and expected catheter duration.
2Optimise infection, skin, nutrition, anaemia and tissue condition; address pain, bowel function, sexual concerns, fertility and future pregnancy.
3Confirm closure and upper-tract drainage after treatment and provide continuing continence, pelvic-floor, psychological and social support.