Go for open surgery ,it is indicated in low & simple fistula.

It’s simple fistula in ano and laser treatment is for complex fistula in ano for any simple fistula treatment surgery is best choice for management so your doctor advise fistulotomy without laser but you can go for laser treatment also

Laser treatment is preferred in non complicated fistula with patent tract. Providing MR fistulogram report would be beneficial for advising

Success Rate vs. Recurrence ​For a low intersphincteric fistula, a traditional fistulotomy is the 'gold standard.' It has a success rate of nearly 95–100%. Laser procedures (like FiLaC), while modern, have significantly higher recurrence rates (the fistula coming back) for this specific type of track. ​2. Minimal Sphincter Involvement ​Because your fistula is 'low,' it involves only a very small, safe portion of the internal sphincter. Opening this track surgically provides a permanent cure with a negligible risk to your continence. ​3. Why Laser Isn't Always Better ​Laser treatments are typically reserved for high or complex fistulas where a traditional cut would involve too much muscle. In your case, using a laser would be less effective and increase the chance that you would need a second surgery later. ​Summary ​The goal is to cure the fistula the first time. A fistulotomy offers you the highest clinical certainty of a permanent cure with minimal risk to your muscle function."

So for your query a simple answer is any fistula surgery can be done but specially for LASER aided treatment , it's needed to be a patent fistula tract with internal and external opening. If internal opening is closed with granulation tissue or epithelialization Or there is associated abscess then LASER treatment till now contraindicated.

Should be needing surgery And the method depends completely on the situation so get a consult from a general surgeon