Psyllium husk doesn't have starch, but it really does a number on me -- I almost got iritis after taking it for a couple days. Popped a couple Aleve to bring the inflammation down, and resolved never to take it again, starch or no...
I think the problem is that no-starch is a simplification, which works for some people but not for tough cases. Some young'uns who have only had AS for a few years can get good results with a diet that is more low-starch than no-starch, and don't have to worry about any other diet subtleties. I don't fall into that category, and based on your introduction you probably don't either... so here are some potential pitfalls to look out for:
* lactose http://en.wikipedia.org/wiki/Lactose
* inulin http://en.wikipedia.org/wiki/Inulin
* FOS http://en.wikipedia.org/wiki/Fructooligosaccharide
I'm going to assume that you've read the theory behind the NSD, which talks about Klebsiella germs living in your gut causing our immune system to go haywire. The point being that anything that increases Klebsiella population in our bodies can make us flare.
The substances in this list are not starch, but they are
complex carbs which Klebsiella germs would be happy to metabolize; the main question is whether they get the chance. Lactose is a difficult sugar for many people to digest. The less efficient your body is at digesting lactose, the more it stays in your gut and feeds the germs. The other two, FOS and inulin, are not directly digestible by humans and always end up fermenting in the gut, but they can be metabolized by beneficial bacteria as well as Klebsiella. So depending on the specific balance of gut flora, they might cause increased Klebsiella population -- or the Klebsiella might get out-competed by other germs.
I think psyllium falls into this same category of potential pitfalls, because it is not absorbed by our digestion but ferments in the gut to feed bacteria. At least, that's the only explanation I came up with for why it caused an inflammation spike.
Hope this made some sense. I've had to learn more about nutrition in the last couple years than I ever wanted to know. Have learned that some of the common knowledge about nutrition turns out to be backwards when dealing with AS, e.g. manufacturers like to brag about including FOS and/or inulin "prebiotics" to encourage beneficial bacterial growth, while in my case they are actually harmful.