Sorry the last response was sooooo long.....
though about it and with less words.....
SCD
eliminates all carb rich foods (All grains, sugar, potatoes ect)
Fodmaps (if done properly) eliminates and reintroduces to test for a reaction, all foods high in fermentablle sugars (including fructose, a monosacaride)
SO...SCD only cares about starchy carbs (because they see them as the root of the problem) and doesn't care about things like fructose and onions.
FODMAPS doesn't care about anything so long as you test for tolerance (tolerance being 'Is there an immediate digestive reaction?), and only of the ones most likely to be causing unwelcome fermentation.
You can do both at once,
an important (nay, vital) part of SCD is the intro diet [1] with a staged reintroduction of foods[2] to see if they are tolerated, so this is when the FODMAPS elimination diet also takes place, Testing FODMAPS tolerance takes place with the SCD reintroduction stages, just don't reintroduce the SCD 'illegals'....
From strict SCD (after bacterial action has been reduced) you can see what needs happening next - for me eliminating dairy (SCD yoghurt) was necessary, and adding in 'safe' carbs (rice, sweet potato) was OK/
Some people might need to be stricter (Paleo AIP with FODMAPS?) before they improve.......
A couple more peoples comparisons/thoughts, (and the first quote really capture the problem with FODMAPS)........
The gut and Paleo, SCD, GAPS, FODMAPs
Elimination diets are not as effective in my opinion, because some foods can create irregularity as late as 1-3 weeks after they’re consumed, making it impossible to know which food was the offending one.
http://eugenia.queru.com/2012/12/08/the-gut-and-paleo-scd-gaps-fodmaps/
Comparison of the FODMAP approach with the Specific Carbohydrate Diet (SCD)
http://www.ibsfree.net/news/2014/4/...roach-with-the-specific-carbohydrate-diet-scd
[1]The SCD Intro Diet
http://pecanbread.com/f/how/introdiet.html
[2]The Stages of SCD
http://pecanbread.com/p/how/stages.html