bowelurinary

Bowel–urinary fistula, also known as a colovesical or entero-vesical fistula, is an abnormal communication between the bowel and the urinary tract. This fistulous tract allows contents from the bowel to enter the bladder or urinary system, leading to a mix of gastrointestinal and urinary symptoms.

The most common cause is diverticular disease, particularly diverticulitis of the sigmoid colon, followed by inflammatory bowel disease such as Crohn's disease, colorectal cancer, prior pelvic radiation, pelvic trauma, or postoperative complications. On occasion, fistulas may arise from infection, mesh erosion, or benign strictures.

Patients typically present with pneumaturia (air in the urine) and feculent or malodorous urine, recurrent urinary tract infections, dysuria, abdominal or pelvic pain, and sometimes changes in bowel habits. Some individuals experience urinary urgency, frequency, or incontinence. Signs of underlying disease (fever, weight loss, anemia) may also be present.

Diagnosis relies on imaging and endoscopy. Contrast-enhanced CT scanning of the abdomen and pelvis is usually the initial test and can reveal a fistula and the involved organs. CT cystography, MRI, or pelvic ultrasound may provide additional detail. Cystoscopy and colonoscopy can help identify the tract's course and underlying disease. Laboratory tests may show infection or inflammation.

Management centers on treating infection and addressing the underlying cause. Antibiotics are used for acute infections. Definitive treatment typically involves surgical repair, such as resection of the diseased bowel segment with closure of the fistula and repair of the bladder; a staged approach or temporary ostomy may be used in select cases. Nonoperative management is limited to specific, well-selected scenarios.

Prognosis varies with the underlying disease and patient health. Early diagnosis and treatment reduce morbidity and complications, such as sepsis or malnutrition.