Can small gallstone 3. 2 mm be dissolved

I had USG to check liver health and along with fatty liver, small gallstone got discovered. I never had any kind of pain but  nausea and little acidity problems. The first report had more clear visibility and measured size was 4 mm. After 1 month in second USG in well known hospital  it was hardly visible as a tiny white spot but not sure why Sonologist gave me clean report stating no calculus and he was not sure it could be a tiny polyp or calculus. Next day I had MRCP and it says 3.2 mm calculus. Wondering if size got reduced or it was not accurate in first USG. What to do now gallstone experts???... I want to avoid any surgery for at least 2-3 years for some reasons . What about ursodiol to dissolve it. Even if it does not dissolve it but it will avoid formation of more stones? What about Ayurvedic and Homeopathic treatment..