I just found a site that has a 58 minute video showing how a doctor in Atlanta cures anal fistulas without cutting them open...And most importantly cures complex multible fistulas in people that suffer with Crohns.
They use a plug made partly from pig guts. They insert this cone shaped plug from the inside where the fistula originates from and stitch it in place. Takes about 2 to 4 weeks to completely heal.
Greatest part of this is when they plug the opening of a complex fistula it cuts off the supply to all other channels and they dry up.