I had two massive rectal fistuals that surfaced an inch from my anos when I was diagnosed with CD in the colon in 2007. I tried the plugs, but they fell out after a couple of weeks. I then had ctons installed to keep the fistulas
open and draining.
GI wanted me to go on remicade, since he said fistula as large as I had never heal by themselves. Instead, I opted to try the SCD diet and if I had no success with that, I could always revert back to remicade. After 6 months of following the diet with 100% fanatical dedication , both fistulas were healed so much, that the surgeon had to remove the ctons so they would heal all the way. All my other CD symtoms like white mucus and blood in my stools were gone also.
I am still following the SCD diet (but not as fanatical), and I have not had one symptom from my CD or any problems with fistulas since 2007. The only maintenence drug I take is pentassa.
The SCD diet doesn't always work for everyone and is difficult to follow, but you have nothing too loose by trying, and all to gain if it works for you. I suggest reading the book, "breaking the vicious cycle" and see what you think.