I haven’t had a fistula. But my Syncrozap always helps heal any sores or inflammation. Also, I use Lugol’s iodine solution. This kindof iodine is made with drinking alcohol rather than isoprophyl alcohol. Unlike other iodines, Lugol’s can be used internally and externally. drclarkstore.com/dr-clark-lugols-iodine-stomach-saver-1-fl-oz-30-cc/