There are anecdotal references to healing without surgery. I’m wondering about this myself. There’s stuff on the web on wheatgrass, diet and hygiene regimen and others. See this below too. Let’s keep talking.
https://www.amazon.com/How-Anal-Fistula-Healed-Naturally-ebook/dp/B07T2JTFRZ/ref=mp_s_a_1_fkmr0_1?dchild=1&keywords=how+i+cured+my+fistula&qid=1609470441&sr=8-1-fkmr0