Differences - SCD Vs FODMAPs

Hi everyone,

I'm doing a bit of research into the two diets, and wondering if anyone more knowledgeable would help me understand why these starchy foods are not allowed in SCD, but allowed in the FODMAP. What is it about the starch that permit them in FODMAP?
- Potatoes
- Rice
- Oats
- Corn

Below are some extracts from the SCD book for reference, but it obviously doesn't really explain why FODMAP permits them.

"Sweet potatoes or yams also contain only amylopectin starch. Vegetables that contain more amylose than amylopectin starch are simpler to digest, because the glucose units which make up all starch molecules are arranged in a linear fashion in amylose starch and are readily exposed to digestive enzymes from saliva and the pancreas. By comparison, amylopectin molecules contain glucose units which form branches . When the amylopectin molecules have been partially digested by pancreatic enzymes, the fragments remaining for the last step in digestion by microvilli enzymes are both maltose and isomaltose."

"The starches in all grains, corn, and potatoes must be strictly avoided. "

"It soon became apparent that grains which contained proteins other than gluten were having deleterious effects on the digestive tract. Some patients suffered relapses and exhibited damaged intestinal cells (microscopically) upon eating soy prod~cts.~~O"a.ts~and barley were found to con- tain gluten-like proteins which offended many celiac suffer- ers." Additional reports implicated rice as being harmful to intestinal cell"