Hi Mark,
Great to hear you found a diet that works. Before I found this site, I found out myself that a keto diet cured my IBS. I did it for a few weeks, but could not get my energy levels sorted out.
I think what makes the diet work is that it shuts out all alergies possible: lactose, fruit, dairy, eggs, what ever you can think of. There is no meat allergy.
Also, I read that plants require sophisticated gut flora to digest, because they developed 'poisonous' mechanisms in evolution to deter creatures from eating them.
Good luck with the diet. I heard a lot of good things about it. I read that it doesn't have to be bad for you. A lot of people seem to be doing great with the diet.
Good luck!