How Can I Confirm If A Painless Pimple Near My Anus Is A Fistula, And Can Fistulas Be Treated With Homeopathic Medicine?

Hi, doctors hope you all are doing well I have a question that I m a previous patient of pernial abcess and I have got a surgery to drain my perinal abcess before almost 3 years from 2 weeks I have a pimple developed near anus nothing is drained from it no pain no fever so how can I confirm that is that a fistula or not another thing that fistula can be treated by using homeopathic medicines?