Im having a similar problem. 4 weeks in I was great but I’m 6 weeks into the diet and I’m gassy all the time and I go from constipation to diarrhea. I don’t get it. I decided to cut oatbran and buckwheat out for the rest of the treatment or at least for 3 months before I reintroduce it. I felt better today by eating smaller meals and waiting at least an hour before drinking water and taking my supplements after meals. This could also be die off. I don’t know. I hope this helps.