From the Guidelines
The initial diagnostic workup for a colovesicular fistula should include a contrast-enhanced CT scan, as it is the most sensitive and specific imaging modality for diagnosing this condition, with the ability to identify the fistula tract, underlying disease, and associated complications 1. The workup for a colovesicular fistula should begin with a thorough history and physical examination, focusing on symptoms like pneumaturia, fecaluria, recurrent urinary tract infections, and abdominal pain. Initial diagnostic tests should include urinalysis, urine culture, complete blood count, and basic metabolic panel.
- Imaging studies are essential, with CT scan with oral and IV contrast being the gold standard diagnostic tool, as it can identify the fistula tract, underlying disease, and associated complications with high sensitivity and specificity 1.
- Colonoscopy should be performed to evaluate for inflammatory bowel disease, diverticulitis, or malignancy as potential causes.
- Cystoscopy can identify the fistula opening in the bladder and allow for biopsy if needed.
- Additional tests may include a barium enema, which can demonstrate contrast material entering the bladder, and cystography.
- MRI may be useful in patients who cannot undergo CT scanning, as it has been shown to be accurate in the diagnosis of colovesical fistula, particularly when repeat imaging is an issue 1.
- Laboratory tests should include inflammatory markers like ESR and CRP to assess disease activity. This comprehensive approach helps confirm the diagnosis, identify the underlying cause, and guide appropriate management, which typically involves surgical intervention after controlling any active infection or inflammation.
From the Research
Diagnostic Workup for Colovesicular Fistula
- The diagnosis of colovesicular fistula is primarily clinical, with symptoms such as pneumaturia and fecaluria present in the majority of cases 2, 3, 4, 5, 6
- Imaging studies play a crucial role in confirming the diagnosis, with the following modalities being used:
- CT scan with rectal contrast, which is the most accurate imaging modality for diagnosing colovesicular fistula 4, 5, 6
- Barium enema, which can detect stricture formation and is useful in diagnosing colovesicular fistula 2, 5
- Cystoscopy, which can detect the fistula and is useful in diagnosing colovesicular fistula 2, 3, 6
- Colonoscopy, which is useful in excluding colonic malignancy and diagnosing colovesicular fistula 2, 5, 6
- The choice of diagnostic modality depends on the clinical presentation and the suspected underlying cause of the fistula 2, 3, 4, 5, 6
Common Causes of Colovesicular Fistula
- Diverticular disease is the most common cause of colovesicular fistula, accounting for approximately 70-90% of cases 2, 3, 5, 6
- Colonic carcinoma is another common cause, accounting for approximately 10-20% of cases 2, 3, 5, 6
- Crohn's disease and other inflammatory bowel diseases can also cause colovesicular fistula, although they are less common causes 2, 6
Treatment Options for Colovesicular Fistula
- Surgical treatment is the most common approach, with resection of the fistula and diseased segment of the intestine being the goal of treatment 2, 3, 5, 6
- The choice of surgical approach depends on the underlying cause of the fistula, the location of the fistula, and the overall health of the patient 2, 3, 5, 6
- Conservative management may be considered in select cases, although it is not a common approach 6