I had two massive rectal fistulas when I was diagnosed with CD in 2007. I was diagnosed with CD in the lower colon and a little bit in the ilium. I had surgey to install ctons to help draining. I was also told by my GI that the only way to heal such large fistuals as I had was with remacaid. He said nothing else will work with fistulas as big as I had.
I really didn't want to turn off my immune system at that time, so I did my own research and decided to try a more conservative approach first, since I was not having any other major symptoms like pain or diarerrhia. I read the book "Breaking the Vicious Cycle" and I decided to try the SCD diet and give it a shot before anything else. I did accept to take pentassa at 1000mg 3Xday, but nothing more hard core.
I followed the SCD diet to the absolute letter without any cheating. I made my own yogurt , i baked my own almond bread, and I followed it to the letter. After 6 months on the diet, the first fistula healed up so much that the surgeon had to remove the cton so it would heal up completely. By the 8 months on the diet the other fistula healed up also. The surgeon asked me what drugs I was taking, and I said none but pentassa and the SCD diet. He said he has never never seen fistulas as big as mine heal by themselves without taking drugs like remacaid. The GI was also amazed. Both docs said what ever you are doing,, just keep it up because it is working for you.
Now was it the pentassa or the SCD diet that healed my fistulas, or maybe the combination of both,,,I guess we will never know, but they healed up and they have never came back. It has been 6 years since my diagnosis, and I have not had one symptom or a flare or any problems with CD since being on the SCD diet. I has a colonoscopy two years ago, and it showed absolutely no inflammation in the colon or ilium. The surgeon said the only signs he saw was some scare tissue around the rectum where the fistulas had been, but nothing more.
I still follow the SCD diet to this day, but a little less strict then before, and I still take the pentassa. I suggest you get the book "breaking the vicious cycle" and read it. It has a a lot of information about CD and how diet affects it. There are also a lot of people on this site that have had good success with the diet so there is wealth of information to be had here. It worked for me healing my fistulas, so it might work for you.