18 months post fistulotomy but still have drainage

I had a chronic anal fissure which turned into an abscess and then fistula. Had a fistulotomy- the wound healed on the outside… but the inside feels like something is wrong. For starters, I still have stool & fluid drainage from the rectum after a BM but also all day. I need a bidet to actually ever be clean. (This is 18 months now post surgery). I am now having pain again (internally) and it feels like either a fissure or maybe another tunnel forming? God knows. I have an apt to get it checked under anesthesia in a couple of days so we’ll see what they find. But the DRAINAGE. Omg why won’t it stop!! Has it happened to you? Is it scar tissue??? What is it!!!