What Happens if a Small Rectovaginal Fistula Passing Only Flatus is Left Untreated?
A small rectovaginal fistula that only passes flatus can be managed conservatively without intervention, and some women may reasonably choose to accept residual fistula drainage over more invasive procedures to optimize their overall quality of life 1.
Natural History and Potential Outcomes
Conservative Management is a Viable Option
For small rectovaginal fistulas with minimal symptoms (flatus only), conservative treatment may be effective and should be attempted for a 3-6 month period 2. The evidence suggests that:
- Small fistulas can close spontaneously with conservative management, particularly when combined with measures to reduce stool liquidity 3
- One case report documented successful closure of a minimal-sized rectovaginal fistula after 22 days of bowel rest with total parenteral nutrition 3
- The symptoms, while distressing, may remain stable without progression in many patients 4
Quality of Life Considerations
The key issue is symptom burden versus treatment risk. The guidelines explicitly acknowledge that:
- Some women may choose to accept residual fistula drainage over proctectomy with an ostomy to optimize their overall quality of life 1
- A fistula passing only flatus represents the mildest form of symptoms on the spectrum
- The psychological and physical impact of living with flatus passage through the vagina must be weighed against surgical risks
Potential Risks of Non-Treatment
Risk of Progression
While the evidence doesn't provide specific data on progression rates for untreated small fistulas, potential concerns include:
- Enlargement of the fistula tract over time, potentially leading to passage of liquid stool or solid feces
- Development of recurrent vaginal or urinary tract infections from bacterial contamination
- Chronic inflammation of surrounding tissues
Rare but Serious Complications
The guidelines note that case reports have identified development of squamous cell carcinoma, basal cell carcinoma, and adenocarcinoma in chronic perianal fistula or sinus tracts in Crohn's disease patients 1. However, this appears to be a rare, long-term complication primarily associated with chronic inflammatory conditions.
Clinical Decision-Making Algorithm
For a small rectovaginal fistula passing only flatus:
- Assess the underlying etiology (obstetric trauma, Crohn's disease, post-surgical, radiation-related)
- Evaluate symptom severity and impact on quality of life
- If symptoms are tolerable to the patient:
- If symptoms are intolerable or the fistula progresses:
- Proceed to definitive treatment based on etiology and complexity
Important Caveats
Context Matters
The appropriateness of conservative management depends heavily on:
- Etiology: Crohn's-related fistulas may require medical therapy to control underlying inflammation 5, 1
- Presence of active rectal inflammation: This must be addressed before any surgical intervention is considered 1
- Patient preferences and tolerance: The decision should be shared with the patient, weighing symptom burden against treatment risks
When Conservative Management is NOT Appropriate
Do not delay treatment if:
- The patient has severe symptoms or psychological distress
- There is evidence of active infection or abscess formation
- The fistula is associated with active Crohn's disease requiring systemic therapy
- There is concern for malignancy in chronic fistulas
Bottom Line
For a small rectovaginal fistula passing only flatus, watchful waiting with conservative measures is a reasonable approach if symptoms are tolerable to the patient. The evidence supports that some patients can live with minimal symptoms indefinitely, and the guidelines explicitly recognize patient choice to accept residual drainage over invasive procedures. However, close monitoring for progression and addressing any underlying inflammatory conditions (particularly Crohn's disease) remains essential.