There is no simple answer to that Amy.
Did you find that the SCD diet helped?
I'm assuming that if he followed SCD for 18 months that it was useful
"So no nuts, avocados, and plant oils of any kind."
If these are the only restrictions then he can continue on SCD or one of the many similar '
paleo based real food diets'
can your son not eat these foods or just not digest them?
"Plant sterols are found in most plant foods with the largest amounts found in vegetable oils and smaller amounts in nuts, legumes, breads and cereal grains, with still smaller amounts in fruits and vegetables."
From your post i get the impression that you will be avoiding foods HIGH in plant sterols, not avoiding all plant sterols.
From my point of view (paleo based) no-one should be eating seed oils anyway, but if you need to avoid coconut oil and olive oil then i can see that it is limiting.....
You can go back to the old fashioned way of cooking with lard, butter and other animal fats.
There is no requirement for nuts in a healthy diet, but the variety is nice.
The problem with SCD is that many things are changed in the diet and there is no way of knowing which factors were important and which had no effect, so there may be many foods that can now be safely reintroduced.
Maybe start by seeing what foods are allowed in similar diets like paleo and PHD (which both allow paleo carbs)
I would start with a list of what foods are allowed on your new restricted diet and then adding a few new (paleo or PHD allowed) foods rather than just giving up (if you found SCD helpful).
The whole idea of the diet is to avoid harmful foods[1] and eat beneficial foods[2] so keep to that principle with foods from similar diets[3]
If you need to replace nut flours in baked goods then try tapioca flour (paleo) or rice flour (PHD).
[1] Bowel Disease, Part II: Healing the Gut By Eliminating Food Toxins
http://perfecthealthdiet.com/2010/0...i-healing-the-gut-by-eliminating-food-toxins/
[2] Bowel Disease, Part III: Healing Through Nutrition
http://perfecthealthdiet.com/2010/07/bowel-disease-part-iii-healing-through-nutrition/
[3]
http://perfecthealthdiet.com/the-diet/