Same thing but no diahreah mine turned out to be gluten intolerance. Completely regular after 3 weeks no gluten. then various problems(disgnosed at 'you know you are getting older') started disappearing, 30 or more in all gone now.
I never had a clue. I had watched a show on 'the Doctors' and decided to try the diet. I knew it was my answer when I had no pain after the first gluten free meal.